625 terms

# BYU Astronomy

Astronomy
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A scientist observes a new phenomenon that disagrees with his explanation or hypothesis. Following the scientific method, he should:

a. reject those observations that do not agree with the theory.
b. wait until someone develops an adequate explanation before announcing his observation.
d.modify his hypothesis.
d.modify his hypothesis.
The study of galaxies gives astronomers important clues about the:

a. origin of intellect.
b.existence of life in the Universe (beyond the Earth).
c.formation of planets.
d.creation of the Universe.
d.creation of the Universe.
An arc second is a measure of:

a. time interval between oscillations of a standard clock.
b. time interval between successive orbital positions.
c. angle.
d. length along a circle.
c. angle.
The number of degrees in a full circle is:

a. 60.
b. 3600.
c. 57.3.
d. 360
d. 360
The average distance from the Earth to the Sun, 149,600,000 km, can be written in shorthand notation as:

a. 1.496 x 10^6 km
b.1.496 x 10^7 km.
c.1.496 x 10^9 km.
d.1.496 x 10^8 km.
d.1.496 x 10^8 km.
An astronomical unit is a unit of:

a. length, the average distance between the Sun and the Earth.
b. length defined as one wavelength of light from krypton gas.
c. time equal to 1 billion years.
d. mass equal to one solar mass.
a. length, the average distance between the Sun and the Earth.
One light year is the:

a. distance that light travels in 1 year.
b. time taken for the Earth to orbit the Sun once.
c. time taken for light to travel from the Sun to the Earth.
d. distance between the Earth and the Sun.
a. distance that light travels in 1 year.
If you were able to travel out into space until the angular distance between the Earth and the Sun was 1 second of arc, how far would you be from the Sun? (Assume that the Earth-Sun line is at right angles to your line of sight.)

a. 1 AU
b.1 pc
c. 1 Mpc (megaparsec)
d.1 ly
b.1 pc
The Orion Nebula is shown on page 5 of the textbook. How long has the light been traveling from this object before it arrives on Earth?

a.4890 years
b.Between 4 and 6 years
c.1500 years
d. 460 years
c.1500 years
Light from a campfire lit by the shepherds at the time of Christ's birth travels out into space at the speed of light. Which is the farthest of the 20 brightest stars beyond which this light will now have traveled?

a.Betelgeuse
b. Sirius
c.Deneb
d. Rigel
d. Rigel
In modern astronomy, the constellations are:

a.88 regions of sky, covering the entire sky.
b.nearby galaxies to which astronomers have given specific names.
c.12 regions of sky through which the Sun, Moon, and planets move as seen from the Earth.
d.clusters of stars that are held together by the mutual gravitational attractions of the individual stars in the cluster.
a.88 regions of sky, covering the entire sky.
The phrase "diurnal motion" refers to the:

a.gradual motion of the constellations from east to west across the sky each night.
b. slow change in position of the constellations from east to west from night to night.
c.apparent motion of the Sun along the ecliptic over the course of a year.
d.change in position of the Moon in the sky as it runs through its phases over the course of a month.
a.gradual motion of the constellations from east to west across the sky each night.
If you watch (or photograph) stars near the north celestial pole for a period of several hours, in what basic pattern do they appear to move?

a. Spirals, as the stars move while the Earth rotates
b.Almost straight lines, rising from the horizon toward the zenith
c. Circles, with the north celestial pole at the center
d.Ellipses, with the north pole at one focus
c. Circles, with the north celestial pole at the center
The apparent path of the Sun across our sky, day by day throughout the year, is known as the:

a. celestial meridian.
b. zenith.
c. ecliptic.
d.celestial equator.
c. ecliptic.
If the Earth's spin axis were perpendicular to the Earth's orbital plane (the ecliptic plane), then the seasons and seasonal variation would be:

a.much faster (shorter seasons), but less severe.
b.nonexistent.
c.much more severe.
d. very little different from the present seasons.
b.nonexistent.
The vernal equinox is that time of the year when the:

a.Sun crosses the equatorial plane or celestial equator, moving south.
b.Earth is at the closest point to the Sun in its elliptical orbit.
c. Sun crosses the equatorial plane, or celestial equator, moving north.
d.Sun crosses the ecliptic plane.
c. Sun crosses the equatorial plane, or celestial equator, moving north.
The approximate date around March 21 represents which season to people living in New Zealand?

a.Beginning of summer
b.Beginning of winter
c. Beginning of spring
d.Beginning of autumn
d.Beginning of autumn
At what approximate value of declination was the Sun on June 21 this year?

a.23.5°
b. 90°
c. 0°
d. -23.5°
a.23.5°
The elevation angle between the northern horizon of a fixed observer and the north celestial pole is equal to:

a.the observer's longitude.
b. a variable value, depending on the time of year.
c. the observer's latitude.
d.the right ascension of the vernal equinox.
c. the observer's latitude.
Where would you have to be to see the north celestial pole in your zenith?

a.The equator
b.The South Pole of Earth
c. About 1° away from the South Pole, to account for precession
d.The North Pole of Earth
d.The North Pole of Earth
Precession is:

a. the daily spinning motion of the Earth.
b.the occasional reversal of the direction of spin of the Earth.
c.the motion of the Earth along its orbital path.
d.a very slow conical motion of the Earth's axis of rotation
d.a very slow conical motion of the Earth's axis of rotation
To what constellation will the north celestial pole be closest in the year 14,000 A.D.?

a. Lyra
b.Cepheus
c. Draco
d.Ursa Major, because the north celestial pole never moves, by definition
a. Lyra
Leap-year corrections in the calendar are necessary to correct for:

a.the offset of the apparent path of the Sun from the celestial equator.
b.the slow drift in the direction of the Earth's spin axis.
c.the fact that one year is not exactly 365 days.
d.errors introduced into the calendar earlier in history by Julius Caesar.
c.the fact that one year is not exactly 365 days.
Which of the following years is not a leap year on the present calendar?

a.2000
b. 2004
c. 2100
d. 1996
c. 2100
Modern astrology is:

a. a precise and accurate guide to the future life and happiness of a child, determined from planetary positions at the moment of its birth.
b.a scientifically unproven and generally useless method for predicting future events in a person's life depending upon planetary positions in the sky.
c. an accurate and reliable way to predict a person's behavior and future from the positions and motions of planets.
d.a reasonable way to use planetary motions to guide one's life.
b.a scientifically unproven and generally useless method for predicting future events in a person's life depending upon planetary positions in the sky.
At what time does a full Moon rise, approximately?

a.At sunrise
b. At midnight
c.At noon
d.At sunset
d.At sunset
If you were standing on the Moon in darkness on the opposite side from the Earth at a particular time, which of the following would be true?

a.You will see the Earth in about 14 days.
b.You will never see the Earth from that position.
c. It will take about half a year before you will see the Earth from that position.
d. You will never see the Sun from this dark side of the Moon.
b.You will never see the Earth from that position.
Eclipses of the Moon can occur only:

a.in the spring and fall seasons, when the Sun is on the ecliptic plane.
b.at full moon.
c. in June and December, when the Sun is near the solstices.
d. at new moon.
b.at full moon.
The phase of the Moon at the time of a solar eclipse:

a.will be new.
b. can be any phase, new, quarter, or full.
c. will be full.
d.will be third quarter.
a.will be new.
Where on Earth would you have to be to observe a particular total solar eclipse?

a.On the dark side of the Earth
b.Within a narrow and specific strip of the Earth's surface, less than 250 km wide
c.Always within 23.5° of the equator (that is, within the tropics)
d.Within 250 km of the Earth's equator
b.Within a narrow and specific strip of the Earth's surface, less than 250 km wide
Which significant observation led the Greeks to accept the idea that the Earth was a sphere?

a.The disappearance of ships as they passed over the Earth's horizon.
b.The shape of the darkening across the Sun's disk during a solar eclipse always appeared circular.
c. The shape of the Earth's shadow on the Moon during a lunar eclipse was always circular.
d.The shape of the eclipse shadow upon Earth during a solar eclipse was always circular.
c. The shape of the Earth's shadow on the Moon during a lunar eclipse was always circular.
Eratosthenes measured the radius of the Earth by:

a. timing the disappearance of the Sun at sunset for two different positions on Earth on the same day of the year.
b.measuring the angular position of the pole star from several positions on Earth.
c. estimating the size of the shadow of the Earth on the Moon during a lunar eclipse.
d.noting the different angles of the Sun at midday on the same day of the year at different positions on Earth.
d.noting the different angles of the Sun at midday on the same day of the year at different positions on Earth.
The ancient Greek astronomer Aristarchus is famous for devising a method for measuring the:

a. precise distance between Alexandria and Syene in ancient Egypt.
b. relative distances of the Sun and the Moon
c. length of an eclipse cycle.
d. diameter of the Earth.
b. relative distances of the Sun and the Moon
Which of the following investigations did the ancient Greeks not carry out?

a.Determination that the Earth is approximately spherical
c.Determination that the Earth's orbit around the Sun is an ellipse
d. Measurement of the relative distances of the Moon and Sun from Earth
c.Determination that the Earth's orbit around the Sun is an ellipse
The correct order of appearance of the following "actors" on the "stage of scientific discovery" is:

a.Ptolemy, Copernicus, Kepler, Newton, Einstein
b. Ptolemy, Kepler, Copernicus, Newton, Einstein
c. Copernicus, Newton, Kepler, Einstein, Ptolemy
d. Ptolemy, Copernicus, Newton, Kepler, Einstein
a.Ptolemy, Copernicus, Kepler, Newton, Einstein
The word "planet" is derived from a Greek term meaning:

a.bright nighttime object.
b. non-twinkling star.
c.astrological sign.
d.wanderer.
d.wanderer.
In the Greek era, it was almost universally believed that the:

a.pole star represented the center of the Universe, about which the Earth and all other objects revolved.
b.Milky Way represented the observable Universe, with its center being the center of the Universe.
c. Earth was at the center of the Universe.
d. Sun was at the center of the Universe.
c. Earth was at the center of the Universe.
Retrograde motion of a planet is:

a.westward motion with respect to the foreground on Earth.
b.westward motion against the star background.
c. eastward motion against the star background.
d.eastward motion with respect to the Moon.
b.westward motion against the star background.
The Almagest is:

a.an ancient book describing the construction of Stonehenge.
b.a Renaissance book describing in detail the development of a heliocentric Universe, with elliptical orbits, the law of equal areas, and the harmonic law.
c.a detailed multivolume account of a heliocentric cosmology produced by ancient Greek astronomers.
d.a collection of ancient data and predictions of positions of the Sun, Moon, and planets, compiled by Ptolemy.
d.a collection of ancient data and predictions of positions of the Sun, Moon, and planets, compiled by Ptolemy.
Which of the following most closely expresses the principle of Occam's razor as it applies to theoretical explanations of physical phenomena?

a. The newest theory is most likely the correct one.
b.The theory that has the longest history is the most likely explanation.
c.The theory requiring the largest number of assumptions is the most likely explanation.
d.The theory requiring few assumptions is the most likely explanation.
d.The theory requiring few assumptions is the most likely explanation.
Copernicus's model for the planetary system:

a. placed the Sun at the center of the solar system and eliminated epicycles completely.
b. retained the Earth at the center of the solar system, but eliminated epicycles.
c. placed the Sun at the center of the solar system, but retained the idea of epicycles.
d. had the Earth at the center of the solar system, and the planets moving in epicycles.
c. placed the Sun at the center of the solar system, but retained the idea of epicycles.
Which of the following objects cannot transit (pass in front of) the Sun when viewed from Earth?

a.Mercury
b.Mars
c.The Moon
d.Venus
b.Mars
When a planet is seen at opposition, it is always at its:

a.most distant point from the Earth.
b. closest point to the Earth.
c.closest point to the Sun.
d. most distant point from the Sun.
b. closest point to the Earth.
Where and when would Venus be seen from Earth when it is at its greatest eastern elongation from the Sun?

a.Just before sunrise, in the east
b. At midnight, in the south
c.Just after sunset, in the east
d. Just after sunset, in the west
d. Just after sunset, in the west
Approximately how many of its sidereal periods has Neptune completed since its discovery in 1846? (see Table of Orbital Data in the Appendix and Box 4-1.)

c. 212
d.147
Tycho Brahe's most important contribution to the development of modern astronomy was the:

a.discovery of the satellites (moons) of Jupiter.
b. use of parallax to prove that the Earth does not move.
c. accurate measurement of planetary positions.
d.proof that planetary orbits are ellipses.
c. accurate measurement of planetary positions.
Kepler as a young man became the assistant to:

a. Nicolaus Copernicus.
b.Sir Isaac Newton.
c. Tycho Brahe.
d.Ptolemy.
c. Tycho Brahe.
At what point in a planet's elliptical orbit is it at its farthest distance from the Sun, measured in kilometers?

a. Aphelion
b. Superior conjunction
c.Opposition
d.Perihelion
a. Aphelion
Kepler's second law states that a planet moves fastest when it:

a.passes through the minor axis.
b. is farthest from the Sun.
c. is at conjunction.
d.is closest to the Sun.
d.is closest to the Sun.
Galileo helped reinforce the notion of a heliocentric theory by:

a.making detailed observations of the moons of Jupiter.
b. noting that the phases of Venus did not match predictions from the geocentric theory.
c.observing that the Moon had craters and mountains.
d.observing that there were stars too faint to be seen without the aid of a telescope.
b. noting that the phases of Venus did not match predictions from the geocentric theory.
On the Moon, where gravity is 1/6 of that on the Earth, which of the following activities would an astronaut not find easier to carry out?

a. Running
b. Long jumping
c.Slowing down and stopping
d.High jumping
c.Slowing down and stopping
If the Earth were to be moved to a distance of 10 AU from the Sun, how much stronger or weaker would the Sun's gravitational force be on the Earth?

a. 10 times stronger
b.100 times weaker
c. 100 times stronger
d.10 times weaker
b.100 times weaker
The first reliable method developed to measure the speed of light involved:

a.carefully observing the motions of the moons of Jupiter at different times in Jupiter's orbit.
b. splitting light into its spectrum in laboratory experiments.
c.observing the opening and closing of shutters on lanterns on hilltops separated by a known distance.
d.carefully measuring the orbital path of the Moon around the Earth.
a.carefully observing the motions of the moons of Jupiter at different times in Jupiter's orbit.
When dropped by an astronaut on the Moon, two objects of different mass have:

a.different accelerations, proportional to their masses.
b.different accelerations, with the more massive object having the smaller acceleration.
c. the same acceleration.
d.no acceleration at all in the airless space.
c. the same acceleration.
Radio waves travel through space at what speed?

a. Much faster than the speed of light
b. At the speed of light, 3 x 10^8m/s
c. Slightly faster than the speed of light, because their wavelength is longer
d. Much slower than the speed of light
b. At the speed of light, 3 x 10^8m/s
Visible light occupies which part of the entire electromagnetic spectrum?

a.Between infrared and ultraviolet
b. Between infrared and microwave
d.Between ultraviolet and X-rays
a.Between infrared and ultraviolet
A perfect blackbody is so named because it:

b. always emits the same amount and color of radiation, regardless of its temperature.
c.only reflects the radiation falling upon it and emits none of its own.
d.absorbs all radiation falling upon it and reflects none.
d.absorbs all radiation falling upon it and reflects none.
As a new star evolves from cool dust and gas to a hot star, the peak wavelength of its spectrum of electromagnetic radiation will:

a. increase from the visible to infrared wavelengths.
b.change from the infrared to the visible wavelengths.
c.remain the same.
d. change from the ultraviolet to the visible range.
b.change from the infrared to the visible wavelengths.
A piece of iron is heated from 400 K to 800 K (127°C to 527°C). By what factor will the total energy per second emitted by this iron increase?

a. 2
b. 296.5
c.4
d.16
d.16
Atoms in a thin, hot gas (such as a neon advertising sign) emit light:

a.at all wavelengths, with the shape of the continuum distribution depending upon the temperature of the gas.
b. only at a specific single wavelength
c. only at visible wavelengths.
d.at specific wavelengths, depending upon the element.
d.at specific wavelengths, depending upon the element.
The physical force that holds the components of an atom together is:

a. the centrifugal force on the electrons, caused by their orbital motion.
b. the electromagnetic attraction between nucleus and electrons.
c.the nuclear force from protons and neutrons.
d.the gravitational force between nucleus and electrons.
b. the electromagnetic attraction between nucleus and electrons.
The parameter of an atom that defines its unique position in the periodic table is:

a. its size.
b.its temperature.
c. the number of protons in the nucleus.
d.the total number of protons and neutrons in the nucleus.
c. the number of protons in the nucleus.
Light that originates in hydrogen atoms in which electrons have jumped from high levels to the level n = 2 will be part of which series of spectral lines?

a. Lyman
b. Balmer
c.Paschen
d. There would be a continuum of light, not a series of lines.
b. Balmer
Ionization of an atom occurs when:

a. the nucleus undergoes fission, or splitting.
b.an electron is lifted from the ground state to an excited level.
c.an electron is removed from the atom.
c.an electron is removed from the atom.
The Doppler effect is the change in the wavelength of light caused by the source:

a. being embedded in a cloud of dust and gas.
b. moving with respect to the observer.
c. being within a high gravitational field.
d.being in an intense magnetic field.
b. moving with respect to the observer.
Match the following bright stars with the constellations in which they belong.

1. Betelgeuse
2. Spica
3. Vega
4.Arcturus

a. Orion
b. Taurus
c. Canis Major
d. Lyra
e. Bootes
f. Virgo
g. Gemini
1. A:Orion
2. F:Virgo
3. D:Lyra
4. E:Bootes
The Zodiac is:

a. a band of bright constellations.
b. a group of bright stars.
c. the constellations through which the Sun appears to travel in one year.
d.a vast collection of stars partially obscured by dark nebulae.
e.a disk-shaped galaxy of stars with the Sun at the center.
c. the constellations through which the Sun appears to travel in one year.
The celestial figure known as the Great Square is found in the constellation of:

a. Perseus.
b. Cygnus.
c.Andromeda.
d.Pegasus.
e.Aquila.
d.Pegasus.
Declination is usually measured north and south from the celestial equator in units of:

a.degrees.
b.seconds of correspondence.
c. hours of time.
d.parallel dimension units.
e. Alfen wavelengths.
a.degrees.
On September 21, the right ascension of the Sun is about:

a. zero hours.
b.6 hours.
c.12 hours.
d. 18 hours.
e. 23.5 hours.
c.12 hours.
The declination of the north celestial pole is:

a. 0°.
b.-90°.
c.-180°.
d.90°.
e.180°.
d.90°.
Polaris, the North Star, does not appear to move in the sky because:

a.the stars are fixed relative to each other.
b. it lies approximately over the northern axis of the Earth.
c. it is too nearby for its motion to be discernible.
d. it is located directly overhead for everyone on Earth.
e. it crosses the Earth-Moon nodal line at one point.
b. it lies approximately over the northern axis of the Earth.
What was the major contribution made by Nicolaus Copernicus to astronomy?

a. He discovered that the planets move around the Sun in elliptical orbits.
b. He said that the Earth is not the center of the Universe.
c. He developed a theory of gravity that could explain orbital motion.
d. He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
e. He made extensive and detailed observations of the positions of the planets.
b. He said that the Earth is not the center of the Universe.
What major contribution to astronomy was made by Tycho Brahe?

a. He discovered that the planets move around the Sun in elliptical orbits.
b.He said that the Earth is not the center of the Universe.
c. He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
d. He made extensive and detailed observations of the positions of the planets.
e.He used his gold nose to finance his observatory.
d. He made extensive and detailed observations of the positions of the planets.
What was the major contribution made to astronomy by Johannes Kepler?

a. He discovered that the planets move around the Sun in elliptical orbits.
b. He developed a theory of gravity that could explain orbital motion.
c.He said that the Earth is not the center of the Universe.
d.He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
e.He made extensive and detailed observations of the positions of the planets.
a. He discovered that the planets move around the Sun in elliptical orbits.
Two forms of electromagnetic radiation that easily penetrate Earth's atmosphere are:

a. X-rays and visible light.
c. ultraviolet and infrared.
e.gamma rays and X-rays.
A hydrogen atom usually consists of:

a. three electrons and a proton.
b. two electrons and a proton.
c. two electrons, two protons, and one tau particle.
d. one electron and a proton.
e. any number of electrons in unspecified locations.
d. one electron and a proton.
The easily recognized star cluster known as the Pleiades is located in the constellation of:

a. Pisces.
c. Taurus.
d. Gemini.
e. Orion.
c. Taurus.
If an object is moving toward you, what effect do you observe in the spectrum of that object?

a.It appears red-shifted.
b. The light appears to be moving faster.
c. All the spectral lines appear broadened.
d.It appears blue-shifted.
e.The light appears brighter.
d. It appears blue-shifted.
What is the principal advantage that orbiting observatories such as the Hubble Space Telescope have over ground-based telescopes?

a.It is above the atmosphere and can see electromagnetic radiation that does not reach the ground.
b. It is the largest telescope ever built in space or on the ground.
c. Its mirror is the most perfect ever built.
d. Its HST instruments are far more sophisticated than any on Earth.
e. It was built with a defective mirror that enabled astronomers to perfect image reconstruction algorithms.
a. It is above the atmosphere and can see electromagnetic radiation that does not reach the ground.
What type of spectrum is seen as light from a hot blackbody source passes through a cooler cloud of gas?

a.Emission line
b. Only the original continuous spectrum will be observed.
c. absorption line
d. A bright line
e. No spectrum will be visible, since the light will all be blocked.
c. absorption line
The series of lines in the spectrum of hydrogen known as the Balmer series are seen in the visible portion of the spectrum and are characterized by electron transitions up from or down to the level n =

a.one.
b. two.
c. three.
d. four.
e.five.
b. two.
Light, when it passes from air into a dense but transparent material such as glass:

a. speeds up.
b. changes its speed to that of sound in the medium.
c. maintains its speed, as required by the laws of physics.
d. slows down.
d. slows down.
A refracting telescope is the type that uses as its main optical element a:

a. mirror.
b.combination of many small plane mirrors.
c.prism of glass.
d. lens.
d. lens.
Who was the first astronomer to build and use a telescope to observe the night sky?

a. Copernicus
b. Newton
c. Tycho Brahe
d. Galileo
d. Galileo
The major reason that astronomers seek funds to build larger telescopes is to:

a.provide magnified images of stars.
b. collect more light from distant objects.
c. measure a wider spectrum of light from stars.
d.bring stars closer to the Earth.
b. collect more light from distant objects.
By what factor is the amount of light gathered by the 10m Keck telescope on Mauna Kea, Hawaii, greater than that gathered by the 2.5m diameter Mount Wilson telescope?

a.4
b.16
c.256
d. 2
b.16
Which of the following types of telescope will suffer from chromatic aberration unless very expensive measures are taken to avoid it?

b. Refracting telescope
c. Cassegrain telescope
d.Reflecting telescope
b. Refracting telescope
A Newtonian telescope uses:

a. only one mirror.
b. two curved mirrors.
c.several mirrors, some curved, some flat, to guide light to a fixed focus with respect to the Earth.
d.one curved mirror and one flat mirror at a 45° angle to the curved mirror.
d.one curved mirror and one flat mirror at a 45° angle to the curved mirror.
When light from the concave primary mirror of a telescope is reflected by a small secondary mirror through a hole in the primary, this is called the:

a. Newtonian focus.
b. Coude focus.
c. Cassegrain focus.
d. prime focus.
c. Cassegrain focus.
A typical photographic plate that is used to photograph astronomical objects through telescopes records about:

a. half of the photons that fall on it.
b. 98% of the photons that fall on it.
c. 25% of the photons that fall on it
d. 2% of the photons that fall on it.
d. 2% of the photons that fall on it.
A spectrograph is usually used in astronomy to measure the:

a. distribution of intensity of light among the various colors.
b. vibration of the Earth following an earthquake.
c.variation of mass of an object as it moves through space.
d.brightness of light at one specific color.
a. distribution of intensity of light among the various colors.
A 10m diameter radio telescope has worse angular resolution than a 1m diameter optical telescope because:

a.angular resolution gets worse as mirror size increases.
b.optical mirrors suffer from chromatic aberration.
c. radio waves have much longer wavelengths than visible light.
d.radio waves have much shorter wavelengths than visible light.
c. radio waves have much longer wavelengths than visible light.
What is the main reason for combining many radio telescopes together into an interferometer, with large distances between telescopes?

a.To ensure that at least one of the telescopes is in a radio interference free zone
b. To ensure that observations are uninterrupted by the failure of one or two telescopes
c. To collect more radiation from very faint sources
d. To obtain much sharper images of sources
d. To obtain much sharper images of sources
The Earth's atmosphere is transparent to which of the following types of electromagnetic radiation?

b. Short ultraviolet wavelengths
c.Long infrared wavelengths
d. X-rays
In which of the following spectral ranges is it essential that astronomical observations be made from space?

a.Visible
b. Far UV
c. Near infrared
b. Far UV
A pair of binoculars is marked 12x50. The magnification of these binoculars is:

a. 600X
b.4.25X
c. 50X
d. 12X
d. 12X
If a telescope with an objective lens of 10-foot focal length is used with an eyepiece of 1/4 inch focal length, the resulting magnification will be:

a.40x.
b.48x.
c.100x.
d. 480x.
e.1000x.
d. 480x.
You are on a strange planet. You note that the stars do not rise and set, but circle around parallel to the horizon. Then you travel over the surface of the planet in a straight line for 4,500 miles and find that at this new place the stars rise straight up from the horizon in the east and set straight down in the west. The circumference of the planet is:

a. 4,500 miles.
b. 9,000 miles.
c. 13,500 miles.
d.14,137 miles.
e.18,000 miles.
e.18,000 miles.
Orange light is of _________ than violet light.

a. lower frequency and longer wavelength
b. higher frequency and longer wavelength
c. lower frequency and shorter wavelength
d. higher frequency and shorter wavelength
e.inverse frequency and reverse wavelength
a. lower frequency and longer wavelength
The horns of the crescent moon always point:

a. toward the south.
b. toward the north.
c. toward the Sun.
d. away from the Sun.
e.away from Venus.
d. away from the Sun.
At new moon the Earth would appear to an observer on the Moon to be at which phase?

a. New
b.First quarter
c. Third quarter
d. Full
e.Crescent
d. Full
When Venus has an elongation that is 20 degrees westward from the Sun, it is then visible:

a. as an evening star.
b. never.
c. all night long.
d. only in the daytime.
e. as a morning star.
e. as a morning star.
What happens in our model of the atom when an emission line is formed?

a. The atom becomes ionized.
b. An electron moves from a higher energy level to a lower one.
c. An ionized atom recombines with a quark.
d. An electron moves from a lower energy level to a higher one.
e. A quark collides with a high-energy positron.
b. An electron moves from a higher energy level to a lower one.
You live at 40° north latitude. How often is the Sun directly overhead at noon in your hometown?

a.Every day
b. Only in the summer
c. Only for the week of the summer solstice
d. Only for one day each year
e. Never
e. Never
The orbit of the Earth about the Sun defines a plane in space. The orbital plane between the Earth and Sun is referred to as the:

a. deferent.
b. ecliptic.
c. elliptic.
d. epicycle.
e.equator.
b. ecliptic.
Although the stellar constellations are of very ancient origin, they still are useful to modern astronomers:

a. for amusement purposes only.
b. as evidence of ancient scientific knowledge.
c. for identifying stars and designating locations on the sky.
d. in casting astrological horoscopes.
e. in regulating the calendar.
c. for identifying stars and designating locations on the sky.
WHO

Was the first person known to suggest the heliocentric model for the solar system

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
1.Aristarchus
WHO

Wrote a series of books called the Almagest in which the epicycle theory of the solar system is described in great detail

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
3.Ptolemy
WHO

Made a remarkably good estimate of the circumference of the Earth during the second century B.C.

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
2.Eratosthenes
WHO

Wrote the book De Revolutionibus Orbium Coelestium published in 1543

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
4.Copernicus
WHO

Discovered the three laws of planetary motion

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
7.Kepler
WHO

Compiled the most accurate set of naked-eye positional observations of the planets that had ever been made up to his time (1600 A.D.)

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
8.Tycho Brahe
WHO

Used eclipses of the moons of Jupiter to estimate the speed of light

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
5.Roemer
WHO

First used a telescope to observe the heavens in 1610

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
6.Galileo
WHO

Discovered the four large moons of Jupiter by direct observation

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
6.Galileo
WHO

Formulated the law of gravitation, the laws of motion, and the nature of light

1.Aristarchus
2.Eratosthenes
3.Ptolemy
4.Copernicus
5.Roemer
6.Galileo
7.Kepler
8.Tycho Brahe
9.Newton
9.Newton
match the following constellations with the bright stars which are found in each.

1.Aldebaran
2.Betelgeuse
3.Deneb

a.Orion
b.Taurus
c.Cygnus
d.Ursa Major
e.Ursa Minor
f.Canis Major
g.Canis Minor
h.Aquila
i.Gemini
1.b.Taurus
2.a.Orion
3.c.Cygnus
match the following constellations with the bright stars which are found in each.

1.Rigel
2.Polaris
3.Sirius

a.Orion
b.Taurus
c.Cygnus
d.Ursa Major
e.Ursa Minor
f.Canis Major
g.Canis Minor
h.Aquila
i.Gemini
1.a.Orion
2.e.Ursa Minor
3.f.Canis Major
match the following constellations with the bright stars which are found in each.

1.Procyon
2.Pollux
3.Altair
4.Castor

a.Orion
b.Taurus
c.Cygnus
d.Ursa Major
e.Ursa Minor
f.Canis Major
g.Canis Minor
h.Aquila
i.Gemini
1.g.Canis Minor
2.i.Gemini
3.h.Aquila
4.i.Gemini
In our solar system, which of the following planets is not a member of the terrestrial group?

a.Venus
b.Mercury
c. Mars
d. Jupiter
d. Jupiter
In our solar system, which of the following planets is not a member of the Jovian group?

a.Mars
b.Saturn
c.Neptune
d. Jupiter
a.Mars
The overall shape of the orbits of most of the planets in the solar system is:

a. elliptical, very elongated.
b. perfectly circular.
c. parabolic.
d. slightly elliptical, but nearly circular.
d. slightly elliptical, but nearly circular.
The planet whose orbit is inclined at the greatest angle to the plane of the ecliptic is:

a. Ceres.
b.Mercury.
c. Uranus.
d. Saturn.
b.Mercury.
The mean (or average) density of a planet is:

a. another way of describing its total mass.
b. its total mass divided by its volume.
c. the mass of a unit volume (1 cubic meter) of the material at its core.
d.the amount of mass in unit volume of the material on its surface.
b. its total mass divided by its volume.
The average density of the massive Jovian planets is:

a. close to the density of basaltic rocks on Earth.
b. much higher than the density of Earth rocks, due to the great gravitational compression of their interiors.
c. close to the density of water.
d. very much less than the density of water, because of the amount of hydrogen they contain.
c. close to the density of water.
The planet whose average density is less than that of water is:

a. Earth.
b. Jupiter.
c. Neptune.
d.Saturn.
d.Saturn.
The smallest terrestrial planet is:

a. Ganymede.
b. Mars.
c. Neptune.
d. Mercury.
d. Mercury.
The asteroid belt exists between the orbits of which planets?

a. Mars and Jupiter
b. Earth and Mars
c. Jupiter and Saturn
d.Venus and Earth
a. Mars and Jupiter
What is the basic difference between comets and asteroids?

a. Comets always move in open orbits around the Sun and hence visit the Sun only once in their lifetime, whereas asteroids move in closed orbits.
b. Comets always emit their own light, whereas asteroids only reflect sunlight.
c. Comets are spherical, whereas asteroids are mostly irregular in shape.
d.Comets are composed mostly of ices, whereas asteroids are composed mainly of rocks.
d.Comets are composed mostly of ices, whereas asteroids are composed mainly of rocks.
Most of the elements beyond H and He in the periodic table in our Sun and solar system most probably originated:

a.from fusion reactions in the centers of earlier stars.
b. from chemical reactions in planetary atmospheres.
c. from the center of our own Sun, through fusion and later ejection as solar wind.
d. in the original Big Bang of the Universe.
a.from fusion reactions in the centers of earlier stars.
The birthplace of the Sun and planets (and of other stars and maybe their planets) is thought to have been:

a. in the centers of galaxies.
b. in cool gas and dust clouds.
c.at the centers of supernovae explosions.
d.in black holes dotted about the Universe.
b. in cool gas and dust clouds.
What name is given to the concentration of mass that formed at the center of the solar nebula and eventually became the Sun?

a. Nebular core
b. Antisun
c. Pseudosun
d. Protosun
d. Protosun
The formation of terrestrial planets around a star is most likely to have occurred by:

a. accretion, or slow accumulation of smaller particles by mutual gravitational attraction.
b. the star's capture of objects traversing the depths of space.
c. condensation of gas from the original star nebula.
d. breakup of a large disk of matter that formed around the star.
a. accretion, or slow accumulation of smaller particles by mutual gravitational attraction.
At what point in time do we say that the protosun became a full-fledged star?

a.When it became hot enough to emit light and heat
b.When the temperature began to rise at its center
c.When planetary formation was complete
d. When thermonuclear fusion reactions began at its center
d. When thermonuclear fusion reactions began at its center
On the big island of Hawaii, the most common type of rocks will be:

a. igneous rocks.
b. metamorphic rocks.
c.meteoritic rocks.
d.sedimentary rocks.
a. igneous rocks.
The auroral display of northern and southern lights in Earth's high atmosphere is caused by:

a. solar wind electrons hitting the high atmosphere after being accelerated by the magnetosphere.
b. fluorescence from solar ultraviolet light.
c. reflection of sunlight from the ice in the polar regions.
d. sunlight scattered by very high atmospheric clouds.
a. solar wind electrons hitting the high atmosphere after being accelerated by the magnetosphere.
The magnetic field of the Earth is caused by:

a.the motion of the solar wind blowing by the Earth.
b.electric currents flowing in the high atmosphere (ionosphere) of the Earth.
c. a solid iron magnet inside the Earth.
d. electric currents flowing in the molten core.
d. electric currents flowing in the molten core.
The major constituents of the Earth's atmosphere are:

a. 77% oxygen, and 21% nitrogen.
b. 95% carbon dioxide, and some water, and vapor.
c. methane, ammonia, water vapor, and carbon dioxide in about equal amounts.
d.77% nitrogen, and 21% oxygen.
d.77% nitrogen, and 21% oxygen.
The Earth has an average density of:

a. 5.5 times that of water.
b. that of water.
c. greater than 10 times that of water.
d. 2 times that of water.
a. 5.5 times that of water.
The age of the Earth is considered to be about:

a. 4.5 billion years.
b. 4.5 million years.
c. 93 million years.
d.10 million years.
a. 4.5 billion years.
Olympus Mons is a:

a.valley on the Moon.
b. mountain on Venus.
c. long-lived anticyclone on Jupiter.
d.volcano on Mars.
d.volcano on Mars.
What is the Caloris Basin?

a.A lunar mare on the far side of the Moon
b.A volcanic caldera on Mount Maxwell, on Venus
c. A large, lowland area on Mars
d.A multi-ringed impact basin on Mercury
d.A multi-ringed impact basin on Mercury
Phobos and Deimos are moons of which planet?

a. Jupiter
b. Mars
c. Venus
d. Uranus
b. Mars
The high mountain range known as Maxwell Montes is found on which planet?

a. Mercury
b. Venus
c. Earth
d. Mars
b. Venus
How was Mercury's true rotation period first measured?

a. By radar from the Earth
b.By measuring the temperature on Mercury's dark side using radio telescopes
c. By monitoring surface features using optical telescopes on Earth
d. By direct photography from Mariner 10
a. By radar from the Earth
Mercury's magnetic field, compared with that of Earth, is:

a. much more powerful.
b. of equivalent strength.
c.extremely weak, so that it cannot prevent the solar wind from hitting the surface of Mercury.
d.weak, but strong enough to deflect the solar wind.
d.weak, but strong enough to deflect the solar wind.
The surface temperature of Venus has been found by radio observations and by remote exploration by Russian spacecraft to be approximately:

a. 300 K.
b. 750 K.
c.273 K.
d. 110 K.
b. 750 K.
Venus has:

a. a magnetic field about the strength of Earth's field.
b.a very powerful magnetic field.
c. no magnetic field.
d.a weak magnetic field about 1/100 of Earth's field strength.
c. no magnetic field.
The surface pressure of the atmosphere of Venus, compared to that of Earth, is:

c. extremely small.
On a topographical map of Venus, how many "continents" of high ground above the flat plains are apparent?

a. 1
b. None
c. 2
d. 7
c. 2
The most common surface features on Venus are:

a. volcanoes and lava flows.
b. ancient river valleys and huge flood plains.
c. impact craters.
d.evidence of plate tectonic motion, including long mountain ranges and subduction troughs.
a. volcanoes and lava flows.
The period and direction of rotation of Mars are:

a. about one Earth day, in the opposite direction to Earth.
b. a little longer than 24 hours, in the same direction as the Earth.
c. about 240 days, in the opposite direction to Earth.
d. just less than 10 hours, in the same direction as Earth.
b. a little longer than 24 hours, in the same direction as the Earth.
Which of the following features have not been seen or detected on Mars?

a.Dust storms
b. Advancing and receding polar ice caps
c.Active volcanoes
d. Valley fog
c.Active volcanoes
The polar caps on Mars are most likely made up of:

a. sulfur dioxide and sulfur compounds.
b. volcanic outflow of light-colored lava and dust similar to that produced by Earth-based volcanoes (such as Mount St. Helens).
c. light-colored dust blown there by intense dust storms.
d.water and CO2 ices.
d.water and CO2 ices.
Maria are:

a. ancient lava flood plains.
b.uplifted regions surrounding large shield volcanoes.
c. ancient riverbeds, now dry.
d. heavily cratered highland regions.
a. ancient lava flood plains.
How quickly is the Moon spiraling away from the Earth?

a.A few centimeters per million years
b. A few centimeters per year
c. A few meters per year
d. A few centimeters per century
b. A few centimeters per year
What is the origin of the majority of lunar craters?

a. Impacts by space probes
b.Surface collapse after loss of groundwater by evaporation
c. Volcanic explosions
d. Impacts by meteoric material
d. Impacts by meteoric material
If astronauts were to establish a permanent settlement at Tranquility Base on the Moon, how many times each year would the Earth rise and set as seen by a resident of this base?

a. 13 times each year
b. Never; the Earth would remain essentially motionless in the sky.
c. 12 times each year
d.Once each year
b. Never; the Earth would remain essentially motionless in the sky.
How many times have human beings landed on the Moon?

a. Seven times
b. Five times
c. Six times
d. Four times
c. Six times
The lunar maria are composed of which of the following rock types?

a. Basalt
b. Limestone
c.Anorthosite
d. Granite
a. Basalt
The theory that seems to account most satisfactorily for the origin of the Moon at the present time is that:

a. a large object collided with the Earth and ejected the material that formed the Moon.
b. the Moon formed from material already in orbit around the Earth.
c. the Moon formed from material spun off from the Earth when the Earth was molten and spinning rapidly, early in its history.
d. the Moon formed by accretion elsewhere in the solar system and was captured later by the Earth.
a. a large object collided with the Earth and ejected the material that formed the Moon.
What is the approximate age of the oldest rocks brought back from the Moon by astronauts during the Apollo program?

a. 4.6 million years
b. 4.6 billion years
c. 10 billion years
d. 3.5 billion years
b. 4.6 billion years
The first man to walk on the Moon in July 1969 was:

a. Buzz Aldrin.
b. John Glenn.
c. Neil Armstrong.
d. Alan Shepard.
c. Neil Armstrong.
The last man to walk on the Moon in December 1972 was:

a. Gene Cernan.
b. Alan Shepard.
c. Harrison Schmitt.
d. Jim Lovell.
a. Gene Cernan.
What is the name of the material from the lunar highlands that is thought to contain material from the original lunar crust?

a. Breccias
b. Anorthosite
c. Basalt
d. Regolith
b. Anorthosite
The first men to orbit the Moon in December 1968 were:

a. Stafford, Young, and Cernan.
b. Armstrong, Collins, and Aldrin.
c. Borman, Lovell, and Anders.
d. Cernan, Evans, and Schmitt.
c. Borman, Lovell, and Anders.
The last men to venture to the Moon in December 1972 were:

a. Stafford, Young, and Cernan.
b. Armstrong, Collins, and Aldrin.
c. Borman, Lovell, and Anders.
d.Cernan, Evans, and Schmitt.
d.Cernan, Evans, and Schmitt.
The rate of erosion on the Moon is practically zero because:

a. of constant meteor impacts.
b. the Apollo landings destroyed the lunar ecosystem.
c. there is no atmosphere, water, or wind.
d. moonquakes continually alter the surface features.
c. there is no atmosphere, water, or wind
Best estimates are that the last major changes occurred to the lunar surface in a time period ending about:

a. 3,000 years ago.
b. 300,000 years ago.
c. 3,000,000 years ago.
d. 3,000,000,000 years ago.
d. 3,000,000,000 years ago.
The rotation periods of Jupiter and Saturn are:

a. long, on the order of several days.
b. very short, on the order of 1 hour.
c. very long, several weeks, because of their great size and mass.
d. relatively short, on the order of 10 hours.
d. relatively short, on the order of 10 hours.
The "snow" that falls continuously on the surface of Io, the innermost Galilean moon of Jupiter, is composed of:

a. water crystals.
b. sulfur and sulfur dioxide.
c. methane crystals.
d. ammonia crystals.
b. sulfur and sulfur dioxide.
What is the composition of Jupiter's clouds?

a. Water ice crystals
b. Liquid droplets of water and ammonia
c. Ice crystals of water and carbon dioxide
d.Ice crystals of methane, ammonia and water
d.Ice crystals of methane, ammonia and water
The reason for the slightly flattened or oblate shape of Jupiter is:

a. its cloud cover (more clouds forming over the equator on average).
b. its rapid rotation rate.
c. that it was formed that way in the beginning and has maintained this shape.
d. the gravitational pull of the Sun and the other planets in the ecliptic.
b. its rapid rotation rate.
Jupiter has a magnetic field that is:

a. variable and often nonexistent, sometimes existing only at the Great Red Spot, which behaves like a sunspot.
b.very strong and localized close to the planet.
c. about the same strength and extent as that of Earth.
d. much stronger than that of Earth, and greatly extended in space.
d. much stronger than that of Earth, and greatly extended in space.
Which satellite of Jupiter is volcanically active?

a. Callisto
b. Io
c. Ganymede
d. Europa
b. Io
The largest satellite (moon) in our planetary system is:

a. Phobos, one of the moons of Mars.
b. Earth's Moon.
c. Titan, a moon of Saturn.
d. Ganymede, a moon of Jupiter.
d. Ganymede, a moon of Jupiter.
The heating that produces volcanic activity on Io, the large Galilean moon of Jupiter, is probably caused by:

a. original heat of formation.
b. tidal distortion by Jupiter and its other moons.
c. nuclear fission within its interior.
d. decay of radioactive elements in its interior.
b. tidal distortion by Jupiter and its other moons.
The faint ring around Jupiter is in:

a. the ecliptic plane.
b. the planet's equatorial plane, tilted 3° to the ecliptic.
c. a plane containing the north and south poles of the planet.
d. the planet's orbital plane, tilted 1.3° to the ecliptic.
b. the planet's equatorial plane, tilted 3° to the ecliptic.
How are the relative ages of the different types of terrain on Ganymede estimated?

a. The lighter the coloration, the older the terrain
b. The denser the cratering, the older the terrain
c. The colder the surface, the older the terrain
d. The smoother the surface, the older the terrain
b. The denser the cratering, the older the terrain
The particles in Saturn's rings:

a. move in circular Keplerian orbits, the inner particles moving fastest.
b. revolve in different directions, depending upon the distance from the planet.
c.move in circular orbits, with the outer particles moving fastest because they are farthest from the planet.
d. all move as if they are one solid disk.
a. move in circular Keplerian orbits, the inner particles moving fastest.
The particles in Saturn's rings are composed of:

a. rocks with the reflectivity of dark asphalt.
b. a mixture of iron and nickel.
c. ammonia and methane ice, possibly with rocky centers.
d. water ice or rock coated with water ice.
d. water ice or rock coated with water ice.
Two tiny but significant satellites that follow nearly identical orbits around Saturn are called "shepherd moons" because they:

a. clear particles from the Cassini division in Saturn's rings.
b. appear to trigger volcanoes or geysers on the surfaces of larger moons by gravitational interaction.
c. seem to trail streams of gases behind them, like comet tails.
d. appear to concentrate particles into the narrow but twisted F ring of Saturn.
d. appear to concentrate particles into the narrow but twisted F ring of Saturn.
The major constituent of Saturn is:

a. rock.
b. nitrogen.
c. hydrogen.
d. carbon dioxide.
c. hydrogen.
Saturn appears to emit heat as infrared radiation in excess of the energy absorbed from sunlight. The most likely major cause of this heating is:

a. the radioactive decay of naturally occurring isotopes in the atmosphere and interior of Saturn.
b. condensation of helium into droplets that fall into the planet, releasing gravitational energy as heat.
c. energy released from the continuous shrinking due to gravity.
d. remnant heat from the original formation of the planet.
b. condensation of helium into droplets that fall into the planet, releasing gravitational energy as heat.
Saturn's moon Titan is different from all other moons of planets because:

a. lakes of water with floating icebergs are seen upon its surface.
b. continuously erupting volcanoes are observed upon it.
c. its orbit carries it directly over both poles of the planet.
d. it possesses a thick atmosphere.
d. it possesses a thick atmosphere.
How was Neptune discovered?

a. By accident, by an astronomer who was conducting a sky survey
b. By a careful search in the 1930s by an astronomer who was convinced it must be there
c. By an astronomer studying old photographs of the sky, several years after they were taken
d. By careful application of Newton's laws to the motions of other planets
d. By careful application of Newton's laws to the motions of other planets
How was Pluto discovered?

a. By the infrared cameras on the IRAS spacecraft
b. By Voyager spacecraft cameras, which were used between planetary encounters to survey the planetary system
c. By prediction, using Newton's laws, to account for the deviations from uniform orbits of Uranus and Neptune
d. By searching photographs of the sky for an object that moved day by day
d. By searching photographs of the sky for an object that moved day by day
One of the major planets has its spin axis tilted almost parallel to its orbital plane. Which planet is this?

a. Neptune
b. Saturn
c. Uranus
d.Mars
c. Uranus
What scientific method was used to discover the rings around Uranus?

a. X-ray photography from space
b. Spacecraft exploration of the planet
c. Occultation of a star as the planet and rings moved in front of it
d. Direct photography from Earth
c. Occultation of a star as the planet and rings moved in front of it
Triton, the giant moon of Neptune, differs from all other major moons of planets in that:

a. it orbits in a retrograde way, opposite to the planet's rotation.
b. its orbit takes it over the planet's poles.
c. its orbit is very elliptical.
d. its orbit lies inside that of the rings of Neptune.
a. it orbits in a retrograde way, opposite to the planet's rotation.
Which one of the following statements correctly describes Miranda, one of the satellites of Uranus?

a. Icy surface with chaotically varied terrain
b. Rocky surface with lava lakes and several active volcanoes
c. Smooth, showing only a network of fine cracks, and very dark (with only 1% reflectivity)
d. Icy, frost-covered surface with vents of rising gas visible in the northern hemisphere
a. Icy surface with chaotically varied terrain
What features characterize the visible surface of Triton, Neptune's largest moon?

a. Relatively smooth areas surrounding "islands" of chaotic terrain
b. Wrinkled surface, frozen lakes, and plumes of nitrogen gas
c. Ice heavily cratered by ancient impacts
d. Lava flows, volcanoes, and sulfur dioxide frost
b. Wrinkled surface, frozen lakes, and plumes of nitrogen gas
What method was recently used to determine the diameters of Pluto and its moon, Charon?

a. Observation of the disappearance of Pluto, and then its moon Charon, behind our Moon in an occultation
b. Photography from a visiting spacecraft
c. Observation of the mutual eclipses of Pluto and Charon
d. Radio interferometry, with arrays of telescopes producing extremely high resolution images
c. Observation of the mutual eclipses of Pluto and Charon
What is unique about the Pluto-Charon system, compared to the classical planets in the solar system?

a. Both Pluto and Charon are volcanically active, with lava flows and vents of sulfur dioxide gas.
b. Pluto has only one satellite.
c.Both Pluto and Charon are in synchronous rotation, so each one always turns the same face to the other one.
d. Although Charon is an icy moon, it is in orbit around a giant planet made mostly of liquid hydrogen.
c.Both Pluto and Charon are in synchronous rotation, so each one always turns the same face to the other one.
Bode's law of planetary distances is:

a. an actual physical law, developed by Bode.
b. precisely correct for all planets, but was not developed by Bode.
c. not a true physical law, and was not discovered by Bode.
d. only an approximate relationship, initially discovered by Bode.
c. not a true physical law, and was not discovered by Bode.
How would a typical asteroid appear on a time exposure photograph of the sky as it orbited the Sun, if the camera were tracking the background stars?

a. It would look like any other star, a small extra dot not shown on star charts of this area of the sky.
b. It would look like a small, diffuse patch against the sharp images of stars because of the dust and gas surrounding it.
c. It would produce a short trail as it moved slowly against the background stars.
d. It would produce a flash of light as it crossed the field of view of the camera.
c. It would produce a short trail as it moved slowly against the background stars.
Most asteroids:

a. have irregular shapes and are covered with very light-colored dust, reflecting sunlight well.
b. are spherical and ice-coated and hence are light-colored and shiny.
c. are dark and spherical in shape, with many craters on their surfaces.
d. are dark, irregular in shape and heavily cratered.
d. are dark, irregular in shape and heavily cratered.
The largest known asteroid in our solar system is:

a. Gaspra.
b. Pallas.
c. Ceres.
d. Titan.
c. Ceres.
The combined matter in the asteroid belt would produce an object of what approximate size?

a. About 1500 km in diameter, significantly smaller than the Moon
b. About the size of Earth
c. Only a few km in diameter, similar to an average mountain on Earth
d. About the size of Mercury
a. About 1500 km in diameter, significantly smaller than the Moon
The Trojan asteroids orbit the Sun in circular orbits at the same distance as:

a.the main asteroid belt.
b. Mars.
c. Jupiter.
d. Earth.
c. Jupiter.
Asteroids whose elliptical orbits have perihelion distances shorter than the Earth's orbital distance are known as:

a. Trojan asteroids.
b. Kirkwood asteroids.
c.Amor asteroids.
d. near-Earth objects.
d. near-Earth objects.
The technique that has proved most useful for determining the shapes of a large number of asteroids has been:

a. measurement of brightness variations as the asteroids rotate.
b. direct photography of the asteroid's shape from Earth.
c. radio interferometry using a worldwide telescope network.
d. photography from spacecraft.
a. measurement of brightness variations as the asteroids rotate.
A piece of rock from outer space that reaches the Earth's surface after surviving a fiery passage through the Earth's atmosphere is known as:

a. an asteroid.
b. a meteorite.
c. a meteor.
d. a meteoroid.
b. a meteorite.
The estimated total infall of meteoritic and extraterrestrial material from space per day upon the Earth is:

c. less than 1 ton.
Perhaps the most interesting material to be found inside rocks that have come to us from outer space is:

b. amino acids, or proteins.
c. pure iron.
d. carbon.
b. amino acids, or proteins.
Most comet nuclei are believed to be:

a. chunks of water and methane ice ejected from the surface of the icy satellites of the outer planets by asteroid impacts.
b. chunks of dusty ice left over from the formation of the solar system.
c.large carbon chondrite meteoroids that have been set on fire by the Sun and are trailing long smoke trails.
d. chucks of rock or iron chipped from asteroids by impacts.
b. chunks of dusty ice left over from the formation of the solar system.
The ionized gas tail of a comet is always aligned with the:

a. comet-Sun line.
b. line between the comet and the nearest planet as it moves in its orbit.
c. comet's direction of motion.
d. celestial equator.
a. comet-Sun line.
The dust tail of a comet has which of the following characteristics?

a. Curved, wide, without structure, and transparent to starlight
b. Spherical, very large, and of low brightness, centered upon the comet nucleus, showing up only on UV photographs
c. Narrow, straight, and pointed directly at the Sun at all times
d. Long, straight, structured, and pointed directly away from the Sun
a. Curved, wide, without structure, and transparent to starlight
A meteor shower results from:

a. a small piece of rock or asteroid fragmenting as it passes through the Earth's atmosphere.
b. a meteor passing through a rain cloud on the Earth.
c. material reentering the Earth's atmosphere after being ejected into space by violent volcanic eruptions on Earth.
d. the Earth passing through debris strewn along a comet's orbit.
d. the Earth passing through debris strewn along a comet's orbit.
Cygnus is from which constellation?:

a.Arcturus
b.Capella
c.Deneb
d.Altair
e.Antares
f.Aldebaran
g.Betelgeuse
h.Vega
c.Deneb
Auriga is from which constellation?:

a.Arcturus
b.Capella
c.Deneb
d.Altair
e.Antares
f.Aldebaran
g.Betelgeuse
h.Vega
b.Capella
Scorpio is from which constellation?:

a.Arcturus
b.Capella
c.Deneb
d.Altair
e.Antares
f.Aldebaran
g.Betelgeuse
h.Vega
e.Antares
Taurus is from which constellation?:

a.Arcturus
b.Capella
c.Deneb
d.Altair
e.Antares
f.Aldebaran
g.Betelgeuse
h.Vega
f.Aldebaran
Which of the following is one of the many contributions Galileo Galilei made to astronomy?

a. He discovered that the planets move around the Sun in elliptical orbits.
b.He developed a theory of gravity that could explain orbital motion.
c. He used his gold nose to finance his observatory.
d. He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
e. He invented calculus to explain the motion of falling bodies in a gravity field.
d. He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
If you view a hot star through a cool cloud of gas, what sort of spectrum are you likely to see?

a. Continuous
b. Emission
c. Absorption
d. Bright line
e. No spectrum will be visible.
c. Absorption
Which of the following properties is constant for all types of electromagnetic waves?

a. Wavelength
b. Speed
c. Energy
d. Frequency
e. Color
b. Speed
Adaptive optics are used to correct what problem?

a.The emission of the Earth's atmosphere
b. Defects in the optics of the telescope
c. Slight errors in the telescope's mount that compensate for the Earth's rotation
d. The reduction of thermal noise in a CCD detector
e. Effects of atmospheric turbulence
e. Effects of atmospheric turbulence
Which of the following is a problem inherent to individual radio telescopes?

a.They are all badly affected by atmospheric conditions.
b. The slightest bit of wind shakes them about, preventing observations.
c. They have poor angular resolution.
d. They have difficulty detecting weak signals.
e. They can only be operated during daytime hours.
c. They have poor angular resolution.
The amount of light reflected by a planet or other object is its:

a. color index.
b. gray scale.
c. emissivity.
d. apparent magnitude.
e. albedo.
c. emissivity.
Which of the following are the Jovian planets?

a. Jupiter, Saturn, Uranus, Neptune, and Pluto
b. Jupiter only
c. Jupiter, Saturn, Uranus, and Neptune
d. Mars, Jupiter, Saturn, Uranus, and Neptune
e. Mercury, Mars, and Pluto
c. Jupiter, Saturn, Uranus, and Neptune
Which of the following defines density?

a. Atomic weight of an object
b. Mass divided by volume
c. Size divided by weight
d.Mass times weight
e. Composition scalar divided by mass
b. Mass divided by volume
How do the densities of the terrestrial and Jovian planets compare?

a. All the planets have similar densities.
b. The Jovian planets generally have higher densities than the terrestrial planets.
c. Generalization cannot be made; one planet is different from the next.
d. Comparisons are useless because the Jovian planets are so much larger than terrestrial planets.
e. The terrestrial planets generally have higher densities than the Jovian planets.
e. The terrestrial planets generally have higher densities than the Jovian planets.
Where are asteroids generally found in the solar system?

a. Beyond the orbit of Uranus
b. Between the orbits of Mars and Jupiter
c. Among the orbits of the terrestrial planets
d. Among the orbits of the Jovian planets
e. Between the orbits of Jupiter and Saturn
b. Between the orbits of Mars and Jupiter
What is the primary ingredient in the Earth's atmosphere?

a. Carbon dioxide
b. Oxygen
c. Neon
d. Hydrogen
e. Nitrogen
e. Nitrogen
Who first postulated and was then ridiculed by most geologists for a theory that proposed that the continents drift around over the Earth's surface?

a. Charles Darwin
b. J. Tuzo Wilson
c. Alfred Wegener
d. James Van Allen
e. Alan Shepard
c. Alfred Wegener
The average rate of erosion on the Moon is far less than that on the Earth because:

a. the crust of the Moon is denser than the Earth's crust.
b. the Moon lacks an atmosphere and free water.
c. the Moon is younger than the Earth.
d. there are no tidal forces acting on the Moon.
e. the Apollo landings destroyed the lunar ecosystem.
b. the Moon lacks an atmosphere and free water.
The constituents of the atmosphere of Mercury can best be described as:

a. hydrogen and helium.
b. methane and ammonia.
c. carbon gas.
d. mostly noble gases such as neon and argon.
e. absent.
c. carbon gas.
What result does the greenhouse effect have on the surface environment of Venus?

a. Little or no effect
b. About the same as on Earth
c. It has reduced the surface temperature by about 30 degrees Celsius.
d. It has raised the surface temperature by hundreds of degrees Celsius.
e. It makes Venus the best place to grow roses in February.
d. It has raised the surface temperature by hundreds of degrees Celsius.
Venus has a feature named Ishtar Terra. What is this feature?

a. A very large volcano
b. A large impact crater
c. A continental-sized plateau
d. A large system of valleys
e. A large basin similar to the maria on the Moon
c. A continental-sized plateau
The thickness of the "photosphere," or the visible "surface" of the Sun, is:

a. 300-400 km.
b. 3,000-4,000 km.
d.several times 10,000 km.
a. 300-400 km.
What causes the granular appearance of the surface of the Sun?

a.Thermonuclear fusion in its interior
b. Convective motion under the solar surface
c. The regular impact of meteoroids and comets onto the solar surface
d. Differential rotation of the surface layers
b. Convective motion under the solar surface
The chemical composition of the surface layers of the Sun is determined primarily by what technique?

a. Theoretical modeling and computer calculation
b. Examination of samples of meteorites
c. Satellite measurements of the solar wind
d. Spectroscopy
d. Spectroscopy
The appearance of the visible spectrum of the Sun, when its light is separated into its component colors, is a/an:

a. continuous bright spectrum, crossed by thousands of dark absorption lines.
b. uniform continuous spectrum with no structure.
c.spectrum containing many dark absorption and many bright emission lines on a continuous background.
d. spectrum consisting only of a few bright emission lines.
a. continuous bright spectrum, crossed by thousands of dark absorption lines.
The temperature of the Sun's photosphere is:

d. close to 1 million K.
The visible corona of the Sun is most effectively photographed:

a. during lunar eclipses, when the sky is darker.
b. in spring and fall, because of the tilt of the spin axis of the Sun.
c. at solar maximum periods, over a period of a few years.
d. during solar eclipses.
d. during solar eclipses.
The temperature of the corona of the Sun is:

a. very hot, about 106 K.
b. about the same as that of the photosphere, 5800 K.
c. about twice as hot as the photosphere, 12,000 K.
d. very cool, because it is farthest from the heat source.
a. very hot, about 106 K.
Coronal holes are thought to be the source of:

a. dust released from the Sun.
b. influence on human behavior (for example, astrology).
c. powerful loops of magnetic field, linked to active regions.
d. the solar wind.
d. the solar wind.
Sunspots are:

a. the shadows of cool, dark curtains of matter, hanging above the solar surface.
b. hotter, deeper regions in the Sun's atmosphere.
c. cooler regions of the Sun's high corona.
d. cooler, darker regions on the Sun's surface.
d. cooler, darker regions on the Sun's surface.
The rotation of the Sun is:

a. fast at mid-latitudes, slow at the equator, and slower near the poles.
b. fast at the equator, slowest at mid-latitudes, rising to intermediate speeds near the poles.
c. slowest at the equator, fast at mid-latitudes, and faster near the poles.
d. fast at the equator, slow at mid-latitudes, and slower near the poles.
d. fast at the equator, slow at mid-latitudes, and slower near the poles.
The major feature that distinguishes a sunspot from other regions on the Sun is:

a. its faster rotation around the Sun's axis than neighboring regions.
b. the much brighter emission of light from it.
c. its very powerful magnetic field.
d. a coronal hole existing above it.
c. its very powerful magnetic field.
The Zeeman effect describes what change in spectral lines?

a. Splitting of lines, because the atoms are within an intense magnetic field
b. Broadening associated with high temperatures
c. The change in relative intensity of different lines from sources of different temperature
d. Their shift because of the movement of the source
a. Splitting of lines, because the atoms are within an intense magnetic field
An arching column of gas suspended over a sunspot group is called a:

a. spicule.
b. coronal hole.
c. prominence.
d. flare.
c. prominence.
Solar magnetic activity at the present time in history seems to vary almost periodically with a time scale of:

a. 22 years.
b. 5 minutes.
c. 100 years.
d. 2 years.
a. 22 years.
In the thermonuclear process that is thought to heat the Sun, the nuclei of which chemical elements are converted to other nuclei to produce the requisite energy?

a. Hydrogen to helium
b. Helium to hydrogen
d. Iron, in a chain reaction, leading eventually to hydrogen
a. Hydrogen to helium
To what do the words "hydrostatic equilibrium" in the Sun refer?

a. The balance of gas pressure inward and heat outward
b. The creation of one helium nucleus for the "destruction" of every four hydrogen nuclei
c. The balance of gravity inward and gas pressure outward
d. The balance of gas pressure outward and magnetic forces inward
c. The balance of gravity inward and gas pressure outward
Of the three ways in which energy is transported in nature, which two are important in the Sun?

c. Convection and conduction
d. The statement is wrong; all three are equally important in the Sun.
The average time taken for energy generated by thermonuclear fusion in the center of the Sun to reach the surface layers and escape is calculated to be:

c. only a few seconds.
The temperature at the center of the Sun, where thermonuclear processes take place, is approximately:

a. 1.5 million K.
b. 1.5 x 107 K.
c. 6000 K.
d. About 4500 K, as shown by sunspots.
b. 1.5 x 107 K.
The solar neutrino experiment designed by Raymond Davis has detected a rate of solar neutrinos arriving at the Earth that is:

a. almost exactly equal to the predicted rate.
b. about 1/3 of the predicted rate.
c. less than 1% of the predicted rate.
d.almost double the predicted rate.
b. about 1/3 of the predicted rate.
Name the second most abundant element in the Sun.

a. Hydrogen
b. Helium
c. Lithium
d. Carbon
e. Oxygen
b. Helium
The planet that rotates on its axis with a period almost identical to that of the Earth is:

a. Mercury.
b. Venus.
c. Mars.
d. Jupiter.
e. Saturn.
c. Mars.
The four giant moons of Jupiter were discovered by:

a. Newton.
b. Galileo.
c. Ptolemy.
d. The Voyager spacecraft.
e.Tycho.
b. Galileo.
Which kind of process, as a net result, supplies the energy of our Sun?

a. Hydrogen atoms are converted to helium through fusion.
b. Uranium splits to form lighter elements through fission.
c.Carbon combines with oxygen to form carbon dioxide.
d. The outer layers collapse toward the center, causing a rise in temperature
a. Hydrogen atoms are converted to helium through fusion.
Suppose you are at the Tropic of Cancer, which has a latitude of 23.5°. The altitude of the north celestial pole as seen from your position is: (This is not a trick question!)

a. 66.5°.
b. 47°.
c. 23.5°.
d. 0°.
e. 90°.
c. 23.5°.
The temperature of the solar photosphere is about:

a. 1,000 K.
b. 4,200 K.
c. 5,800 K.
d. 8,400 K.
e. 9,600 K.
c. 5,800 K.
The existence of the Great Red Spot of Jupiter has been observed using telescopes since:

a. the first flyby of a spacecraft, Pioneer 10, in December, 1973.
b. the arrival at Jupiter of Voyager 1 with its imaging cameras, in 1979.
c. the 200-inch telescope on Mount Palomar, in 1948.
d. the 1600s.
e. around 1950.
d. the 1600s.
Which of these is least important to an astronomer for observing stars?

a. Magnifying power
b. Resolving power
c. Ability to photograph or measure for long periods of time
d. Light-gathering power
e. Ability to aim the telescope in different directions
a. Magnifying power
An eclipse of the Sun can only occur when the Moon is at:

a. full moon.
b. new moon.
c. zerogee.
d. perigee.
e. apogee.
b. new moon.
How was Uranus discovered?

a. By an astronomer studying old photographs of the sky, several years after they were taken
b. By using the first closed form solution to the three body gravitation problem
c. By careful application of Newton's laws to the motion of other planets
d. By accident, by an astronomer who was conducting a sky survey
e. By a careful search in the 1930s by an astronomer who was convinced it must be there
d. By accident, by an astronomer who was conducting a sky survey
Suppose you see the Moon in the sky one evening. The next evening, it will have moved:

a. to the east.
b. to the west.
c. to the north.
d. to the south.
e. not at all.
a. to the east.
In 1928 the International Astronomical Union divided the entire sky into ______ officially recognized constellations.

a. 12
b. 24
c. 36
d. 66
e. 88
e. 88
Observation of the shift of a star's spectrum toward the red or the blue enables us to determine the star's:

a. proper motion.
b. temperature.
c. distance.
d. spectral type.
Jupiter's 55 small outer satellites (moons) appear to be:

a. rocky or icy debris left over from the formation of the Jovian satellite system.
b. dust grains.
c. asteroids captured by Jupiter.
d. about the same size as our Moon or Mercury.
e. part of the Oort cloud.
c. asteroids captured by Jupiter.
The Zeeman effect describes what changes in spectral lines?

b. Signs of recombination oscillator strengths
c. Intensity changes due to temperature changes
d. Shifting due to source movement
e. Line splitting due to intense magnetic fields
e. Line splitting due to intense magnetic fields
Moon of Neptune with a thin atmosphere:

a.Titan
b.Triton
c.Titania
d.Titanic
e.Miranda
f.Mimas
g.Metis
b.Triton
Moon of Saturn that resembles the "Death Star"

a.Titan
b.Triton
c.Titania
d.Titanic
e.Miranda
f.Mimas
g.Metis
f.Mimas
Moon of Neptune with a retrograde orbit

a.Titan
b.Triton
c.Titania
d.Titanic
e.Miranda
f.Mimas
g.Metis
b.Triton
Geologically diverse satellite of Uranus

a.Titan
b.Triton
c.Titania
d.Titanic
e.Miranda
f.Mimas
g.Metis
e.Miranda
Moon of Saturn with a thick atmosphere

a.Titan
b.Triton
c.Titania
d.Titanic
e.Miranda
f.Mimas
g.Metis
a.Titan
Largest rocky surface of any known satellite

a.The Moon
b.Charon
c.Chiron
d.Callisto
e.Grandura
f.Ganymede
g.Europa
f.Ganymede
Earth

a.The Moon
b.Charon
c.Chiron
d.Callisto
e.Grandura
f.Ganymede
g.Europa
a.The Moon
Pluto

a.The Moon
b.Charon
c.Chiron
d.Callisto
e.Grandura
f.Ganymede
g.Europa
b.Charon
First orbited by Borman, Lovell, and Anders in 1968

a.The Moon
b.Charon
c.Chiron
d.Callisto
e.Grandura
f.Ganymede
g.Europa
a.The Moon
Large satellite of Jupiter with possible oceans of water under a layer of ice

a.The Moon
b.Charon
c.Chiron
d.Callisto
e.Grandura
f.Ganymede
g.Europa
g.Europa
Shepherd moon of Saturn

b.Ecliptica
c.Pandora
d.Phobos
e.Proteus
f.Phoebe
g.Portia
h.Io
c.Pandora
Mars

b.Ecliptica
c.Pandora
d.Phobos
e.Proteus
f.Phoebe
g.Portia
h.Io
d.Phobos
Highest albedo of any solar system object

b.Ecliptica
c.Pandora
d.Phobos
e.Proteus
f.Phoebe
g.Portia
h.Io
Innermost Galilean satellite

b.Ecliptica
c.Pandora
d.Phobos
e.Proteus
f.Phoebe
g.Portia
h.Io
h.Io
Galilean satellite with sulfur volcanoes

b.Ecliptica
c.Pandora
d.Phobos
e.Proteus
f.Phoebe
g.Portia
h.Io
h.Io
Parallax of a nearby star is used to estimate its:

a. physical size or diameter.
b. distance from Earth.
c. apparent magnitude.
d. surface temperature.
b. distance from Earth.
How many stars (other than the Sun) have a stellar parallax greater than 1 second of arc?

a. Eight
b. Only one
c. More than 100
d. None
d. None
If the Hipparchos satellite measures the parallax motion of a star against the background stars and concludes that the star has a parallax of 0.01 arc second, how far is that star from us?

a. 1 pc
b. 10 pc
c. 100 pc
d. 1000 pc
c. 100 pc
The proper motion of a star is:

a. the speed of the star in km/s, measured in a direction perpendicular to the line of sight from the Earth to the star.
b. the diameter of the circle through which the star appears to move in the sky each year due to the motion of the Earth.
c. the speed of the star in km/s, measured along the line of sight from the Earth to the star.
d. the angle through which the star moves across our sky against the background stars each year.
d. the angle through which the star moves across our sky against the background stars each year.
Suppose that two identical stars (having the same total light output or luminosity) are located such that star A is at a distance of 3 pc and star B is at a distance of 15 pc. How will star B appear, compared to star A?

a. Star B will be 1/20 as bright as star A
b. Star B will be 1/5 as bright as star A
c. Star B will be 1/2.2 as bright as star A
d. Star B will be 1/25 as bright as star A
d. Star B will be 1/25 as bright as star A
The luminosity of a star is a unique measure of its:

a. velocity of recession away from us.
b. temperature.
c. total energy output.
d. physical size.
c. total energy output.
What does apparent magnitude tell us about a star?

a. The brightness of a star as it appears in our sky
b. The brightness the star would appear to have if it were exactly 10 pc from the Earth
c. Its size compared to the Sun
d. The intrinsic brightness of a star (the total light actually emitted by the star)
a. The brightness of a star as it appears in our sky
Two stars that differ from each other by five magnitudes have a ratio of brightness of:

a.10.
b. 25.
c.100.
d.5.
c.100.
The absolute magnitude of a star is the brightness the star would appear to have if it were placed at what distance from Earth?

a. 1 astronomical unit
b. 10 light years
c. The distance to the galactic center
d. 32.6 light years
d. 32.6 light years
The technique called photometry in stellar astronomy is the measurement of:

a.the arrival times of photons from variable and pulsating stars, from which the pulsation or rotation periods of these stars can be determined.
b. the intensity of light from stars through several limited-bandpass filters from which various stellar characteristics, such as surface temperature, variability, and luminosity can be determined.
c. the precise positions and relative motions of stars in the Galaxy, from which galactic structure and overall rotation can be determined.
d. the relative absorption of light by different atoms and molecules in high resolution spectra of starlight, from which stellar temperatures can be estimated.
b. the intensity of light from stars through several limited-bandpass filters from which various stellar characteristics, such as surface temperature, variability, and luminosity can be determined.
The ratio of brightnesses of a star at two different colors, blue and visual, is a direct measure of what property of the star?

a. Surface temperature
b. Distance from Earth
c. Luminosity
a. Surface temperature
The chemical makeup of a star's surface is usually determined by:

a. theoretical methods, considering the evolution of the star.
b. taking a sample of the star's surface with a space probe.
c. examining the chemicals present in a meteorite.
d. spectroscopy of the light emitted by the star.
d. spectroscopy of the light emitted by the star.
The spectrum of an ordinary main sequence star is a:

a. series of emission lines (mostly from hydrogen, the major constituent of stellar surfaces), which occasionally overlap to produce sections of continuous color.
b. continuum of colors, crossed by brighter lines caused by emission from the hot atoms and molecules on the star's surface.
c. smooth continuum of color, peaking at a specific wavelength whose position is dependent on the star's surface temperature.
d.continuum of colors crossed by dark absorption lines, caused by absorption by cooler atoms and molecules at the star's surface.
d.continuum of colors crossed by dark absorption lines, caused by absorption by cooler atoms and molecules at the star's surface.
The spectral type of a star is most directly related to (and defines uniquely) its:

a. absolute magnitude.
b. surface temperature.
d. luminosity.
b. surface temperature.
Which of the following spectral classification of stars is in correct order of increasing temperature?

a. ABFGKMO
b.KMGFABO
c. OBAFGKM
d. MKGFABO
d. MKGFABO
The spectral class of the Sun is G2 and that of the star Enif is K2. From this information, we know with certainty that Enif is:

a. hotter than the Sun.
b. intrinsically fainter than the Sun.
c. intrinsically brighter than the Sun.
d. cooler than the Sun.
d. cooler than the Sun.
In the spectral classification of stars, strong absorption lines of which of the following atomic or molecular constituents would indicate a very low surface temperature?

a. Mg II
b. Fe II
c.TiO
d. He II
c.TiO
Which two vital parameters are used to describe the systematics of a group of stars (for example, a cluster) in the Hertzsprung-Russell diagram?

a. Mass and apparent magnitude
c. Surface temperature and mass
d. Luminosity and surface temperature
d. Luminosity and surface temperature
Which of the following four spectral-luminosity classes would correspond to a red supergiant?

a. G2 III
b. M2 I
c. M3 V
d. B7 I
b. M2 I
The spectral-luminosity class of the star Spica is B1 V and that of the star Tau Ceti is G8 V. From this information (with luminosity measured in solar luminosities), we know for sure that:

a. Tau Ceti is hotter but has the same luminosity as Spica.
b.Tau Ceti is hotter and has a lower luminosity than Spica.
c. Tau Ceti is cooler but has the same luminosity as Spica.
d. Tau Ceti is cooler and has a lower luminosity than Spica.
d. Tau Ceti is cooler and has a lower luminosity than Spica.
The space between stars is now known to contain:

a. large quantities of dust that absorb light but no gas, either atomic or molecular.
b. variable amounts of gas but no dust, which forms only in planetary systems near stars.
c. dust and gas, both atomic and molecular.
d. a perfect vacuum.
c. dust and gas, both atomic and molecular.
The predominant color of an emission nebula is:

a. green-yellow, from the 530.3 nm emission line of ionized iron, equivalent to that from the hot solar corona.
b.a continuum of all colors, the combined light from all the stars.
c. blue, from scattering of light from hot stars by dust particles.
d. red, from the Balmer Hα line.
d. red, from the Balmer Hα line.
The bright stars at the center of an H II region (emission nebula) are:

a. young O and B stars.
b. red supergiants.
c. hot white dwarfs.
d. T Tauri stars.
a. young O and B stars.
The distinctive color of a reflection nebula is:

a. light of all colors, but predominantly in the red part of the spectrum, emitted by cool stars and reflected by crystals of water ice surrounding the stars.
b. blue, caused by the scattering of light from dust grains.
c.red, coming from the emission of light from hydrogen gas.
d.several specific colors, coming from fluorescence of atoms excited by ultraviolet radiation emitted by hot stars.
b. blue, caused by the scattering of light from dust grains.
The effect of interstellar dust on starlight is:

a. almost nothing, because light does not interact with dust.
b. to dim and redden distant stars by preferentially scattering their blue light.
c. to scatter the red light from stars preferentially, making them appear bluer than expected.
d. to make stars appear less bright than expected, by absorbing light about equally at all wavelengths.
b. to dim and redden distant stars by preferentially scattering their blue light.
New stars are formed from:

a. supernova remnants.
b. activity in the centers of galaxies.
c. free space out of pure energy.
d. huge, cool dust and gas clouds.
d. huge, cool dust and gas clouds.
What fraction of the mass of the Universe is hydrogen (as represented by the "standard cosmic abundances" in the interstellar medium)?

a. 1%
b. 74%
c. 25%
d. 98%
b. 74%
What fraction of the mass of the Universe is helium (as represented by the "standard cosmic abundances" in the interstellar medium)?

a. 1%
b. 8%
c. 74%
d. 25%
d. 25%
The major source of energy in the pre-main-sequence life of the Sun was:

a. burning of carbon atoms.
b. nuclear fission.
c. gravitational.
d. nuclear fusion.
c. gravitational.
The smallest mass that a main sequence star can have is about 0.08 solar mass. This is because:

a.protostars cannot form with masses less than 0.08 solar mass.
b. thermonuclear reactions begin so suddenly in stars of less than 0.08 solar mass that the star is disrupted by an explosion.
c. protostars of less than 0.08 solar mass are not massive enough to contract.
d. the temperature in a contracting protostar of less than 0.08 solar mass does not get high enough for nuclear reactions to start.
d. the temperature in a contracting protostar of less than 0.08 solar mass does not get high enough for nuclear reactions to start.
What occurrence defines the end of the protostar phase of a star's life and the start of the main sequence phase?

a. Convection begins in its interior.
b. Nuclear reactions begin in its core.
c. It begins to expand to become a red supergiant.
d. It stops accreting mass from the interstellar cloud.
b. Nuclear reactions begin in its core.
A T Tauri star is at what stage of its stellar evolution?

a. At the end of its life, decaying away and cooling
b. Protostar, before main sequence phase
c. Just before red giant phase, when variability begins
d. A well-established main sequence star
b. Protostar, before main sequence phase
Herbig-Haro objects (bright, variable regions within nebulae) are now thought to be the result of:

a. the initial condensation of matter into a protostar, producing an infrared and visible glow.
b. intense jets of material ejected from a young star, hitting parts of the nebula.
c. the hot atmosphere of a star as it is ejected in the dying phases of the star's life.
d. brightening of the gas surrounding a massive star as the precursor to a supernova explosion.
b. intense jets of material ejected from a young star, hitting parts of the nebula.
Which range of wavelengths of electromagnetic radiation is most effective in the study of newborn protostars in their dust clouds and nebulae?

a. Ultraviolet
b. Gamma rays
d. Infrared
d. Infrared
Where in the Universe would you look for a protostar?

a. In globular clusters of stars
b. In dense dust and gas clouds
c. Near black holes
d. In the empty space between galaxies
b. In dense dust and gas clouds
How long will the Sun have spent as a main sequence star when it finally begins to evolve toward the red giant phase?

a. 10^11 years
b. 1 billion years
c. 10^10 years
d. 1 million years
c. 10^10 years
How is the length of a star's lifetime related to the mass of the star?

a. Higher mass stars run through their lives faster and have shorter lifetimes.
b.A star's lifetime does not depend on its mass.
c. The lifetimes of stars are too long to measure, so it is not known how (or if) their lifetimes depend on mass.
d. Lower mass stars run through their lives faster and have shorter lifetimes.
a. Higher mass stars run through their lives faster and have shorter lifetimes.
The evolution of a star depends predominantly upon its:

a. location in the Galaxy.
b. chemical composition.
c. initial mass.
d. surface temperature.
c. initial mass.
What happens to the helium-rich core of a star after the core runs out of hydrogen?

a. It contracts and heats up.
b. It expands and cools down.
c. It heats up and expands.
d. It cools down and contracts
a. It contracts and heats up.
The majority of the elements heavier than hydrogen and helium in the Universe are believed to have originated in:

a. the central cores of stars.
b. the original Big Bang.
c. giant molecular clouds.
d. HII regions, under the action of Hα light.
a. the central cores of stars.
The "helium flash" is another name for:

a. a sudden onset of helium fusion reactions in the core of a low-mass red giant star.
b. a sudden onset of helium fusion reactions in red giant and supergiant stars of any mass.
c. a sudden release of energy at the end of helium burning, due to core contraction.
d.the sudden appearance of helium during a supernova explosion (the explosion of a star at the end of its life).
a. a sudden onset of helium fusion reactions in the core of a low-mass red giant star.
The study of stars in clusters has helped astronomers to understand:

a. the mechanism of mass loss in stars.
b. the action of nuclear fusion in stars.
c. the reason for differences in surface temperatures of stars.
d. stellar evolution, the development of stars with time.
d. stellar evolution, the development of stars with time.
Which of the following statements is not true of a globular cluster?

a. It has a round shape.
b. It contains significant amounts of dust and gas surrounding the stars.
c. It can contain up to a million stars.
d. It contains only low-mass stars.
b. It contains significant amounts of dust and gas surrounding the stars.
The Hertzsprung-Russell diagram of a globular cluster does not contain any stars with high luminosity and high temperature on the main sequence because:

a. these high-mass stars evolved away from the main sequence long ago.
b. the stars that were in this position on the main sequence have undergone the usual splitting into binary stars and hence appear lower down on the diagram.
c. stars that will occupy this position on the main sequence have not yet evolved there from the protostar stage.
d.this type of cluster contains only low-mass stars and has never had such stars on its main sequence.
a. these high-mass stars evolved away from the main sequence long ago.
The age of a cluster of stars can be judged by the:

a. amount of radioactive elements detected on star surfaces.
b. total number of stars within the cluster.
c. turnoff point on the main sequence of its H-R diagram.
d. number of novae per year occurring within the cluster.
c. turnoff point on the main sequence of its H-R diagram.
Of the following astronomical objects or systems, which is likely the oldest?

b. The Sun
c. Globular cluster
d. A T Tauri star
c. Globular cluster
An astronomer plots the H-R diagram of a star cluster and finds that it contains hot B-type stars on the main sequence and cooler G and K-type stars noticeably above the main sequence. This cluster is:

a. impossible, because one cannot have cool stars above the main sequence when hot stars are on the main sequence.
b. old, because the G and K stars are already evolving off (away from) the main sequence.
c. of indeterminate age, because one cannot estimate the age of the cluster from the information given.
d. very young, because the G and K stars are still evolving toward the main sequence.
d. very young, because the G and K stars are still evolving toward the main sequence.
The stars at the turnoff point in the H-R diagram of the Hyades star cluster have an absolute magnitude of approximately M = +2, while those at the turnoff point in the cluster M41 have M = 0. From this information, we can say with certainty that the Hyades cluster:

a. is younger than M41.
b. is farther away than M41.
c. has more stars in it than M41.
d. is older than M41.
d. is older than M41.
On the Hertzsprung-Russell diagram, in which direction does the position occupied by a star move after hydrogen burning ends in the star's core?

a. Toward the upper right
b. Toward the lower left
c. Toward the upper left
d. Toward the lower right
a. Toward the upper right
Which of the following stars are metal poor?

a. Population I stars
b. Population II stars
c. Very young stars
d. Open cluster stars
b. Population II stars
Which of the following apparent magnitudes is the brightest?

a. 5.0
b. 15.8
c. 26.9
d. -0.1
e. -1.4
e. -1.4
Which of the following spectral types is the hottest?

a. G2
b. G3
c. G4
d. G5
e. G6
a. G2
A nearby star has a parallax of 0.2 arc seconds. What is its distance?

a. 0.1 pc
b. 0.2 pc
c. 0.5 pc
d. 2 pc
e. 5 pc
e. 5 pc
What physical property of a star does the spectral type measure?

a. Luminosity
b. Temperature
d. Mass
e. Composition
b. Temperature
The H-R diagram is a plot of:

a. luminosity versus mass.
c. luminosity versus temperature.
e. temperature versus mass.
c. luminosity versus temperature.
Which of the following distances is the largest?

a. One astronomical unit
b. One angstrom
c. One nanometer
d. One parsec
e. One light year
d. One parsec
Two stars that differ from each other by five magnitudes differ in brightness by a factor of:

a. 2.5.
b. 10.
c. 25.
d. 100.
e. 250.
d. 100.
Which range of electromagnetic radiation is useful for observing newborn protostars within their gas and dust nebulae?

a. Ultraviolet
b. Highly penetrating x-rays
c. Graphite
d. Visible
e. Infrared
e. Infrared
A typical solar-type star spends most of its life:

a. as a protostar.
b. in explosions lasting millions of years.
c. as a red giant or supergiant.
d. as a main sequence star.
e. as a brown dwarf.
d. as a main sequence star.
What characteristic of a star cluster is used to determine its age?

a. The number of red giants
b. The faintest stars seen in the cluster
c. The main sequence turnoff
d. The total number of stars in the cluster
e. The height of the horizontal branch
c. The main sequence turnoff
How far is the nearest star beyond the Sun?

a. Between 1/2 and one parsec away
b. Between one and two parsecs away
d. Between four and six parsecs away
b. Between one and two parsecs away
I'll bet you thought I would not ask another of these silly constellation questions! Here goes. The bright star Rigel is found in the constellation of:

a. Leo Minor.
b. Orion.
c. Canis Minor.
d. Arcturus.
e. Ursa Major.
b. Orion.
What is not the same for each star in a cluster?

a. Approximate age
b. Mass
c. Composition
d. Distance from Earth
e. Relative heavy element abundance
b. Mass
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star has the bluest color?
a. A
b. B
c. C
d. D
e. E
b. B
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star has the greatest intrinsic luminosity?
a. A.
b. B.
c. C.
d. D.
e. E.
d. D.
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star appears the brightest?
a. A
b. B
c. C
d. D
e. E
c. C
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star is the most distant?
a. A
b. B
c. C
d. D
e. E
e. E
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star is reddest?
a. A
b. B
c. C
d. D
e. E
d. D
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

In which star's spectrum are the hydrogen lines strongest?
a. A
b. B
c. C
d. D
e. E
a. A
Star:
1. A
2. B
3. C
4. D
5. E
Apparent Magnitude
1. 3
2. 5
3. 1
4. 10
5. 15
Absolute Magnitude
1. 1
2. 2
3. 5
4. -4
5. 0
Spectral Type
1. A2
2. O9
3. G5
4. K5
5. F3

Which star is closer to us than 10 parsecs?
a. A
b. B
c. C
d. D
e. E
c. C
What proportion of visible stars in the nighttime sky are multiple star systems, such as binary stars?

b. Less than 1%
c. Nearly 100%
How do two unequal-mass stars move around each other, in general, in a binary system?

a. The low-mass star moves in a circular orbit around the stationary high-mass star.
b. In elliptical orbits, about a common "center of mass"
c. In a common elliptical orbit, always remaining diametrically opposite to each other through one of the foci of the ellipse
d.In straight lines, back and forth past each other
b. In elliptical orbits, about a common "center of mass"
Which important stellar parameter can be determined by the study of binary stars?

a. Surface temperatures of the stars
b. The age of the stars
c. The distance of the stars from Earth
d. Stellar mass
d. Stellar mass
The relationship between mass and luminosity of stars on the main sequence is that:

a. the luminosity of stars rises to a peak at around 1 solar mass and decreases as mass increases beyond this limit.
b. the greater the stellar mass, the larger the luminosity.
c. luminosity is independent of the stellar mass.
d. the greater the stellar mass, the smaller the luminosity.
b. the greater the stellar mass, the larger the luminosity.
Vega is an AØ V star with a surface temperature of about 10,000 degrees. Use Figures 19-13 and 19-21 in your text to estimate the mass of Vega.

a. Between 3.0 and 5.0 solar masses
d. Between 1.5 and 2.0 solar masses
d. Between 1.5 and 2.0 solar masses
The spectrum of a very distant star shows spectral absorption lines of ionized helium, He II, and molecular absorption bands from titanium oxide, TiO. What would be your conclusion about this star?

a. There must be cool, interstellar gas containing TiO between the star and Earth.
b. It is obviously the spectrum of a binary system, two stars close together, a hot star and a cooler companion, unresolved as separate stars from our distance but contributing separate spectra.
c. The star must have a thick, cool atmosphere overlying a hot stellar atmosphere.
d.There must be a very hot atmosphere containing helium gas, overlying a much cooler stellar surface.
b. It is obviously the spectrum of a binary system, two stars close together, a hot star and a cooler companion, unresolved as separate stars from our distance but contributing separate spectra.
What is the physical reason for the appearance of periodic splitting and recombining of spectral lines in the spectra of binary stars?

a. Distortion of atoms on one star by the gravitational force of the other star, leading to line splitting
b. Oscillations on the surfaces of the stars, leading to Doppler-shifted lines
c. Zeeman splitting of spectral lines on one star by the magnetic field of the second star
d. Doppler shift of light from stars orbiting each other, and moving toward and away from Earth during this orbital motion
d. Doppler shift of light from stars orbiting each other, and moving toward and away from Earth during this orbital motion
An eclipsing binary system is:

a. two stars that periodically eclipse each other, as seen from Earth.
b. two stars, detected as such by movement of lines in their spectra by varying Doppler shifts.
c. a star that is periodically eclipsed by the Moon.
d. two stars clearly separated, when viewed from Earth.
a. two stars that periodically eclipse each other, as seen from Earth.
A Cepheid variable is a:

a. low-mass red giant that varies in size and brightness in an irregular way.
b. type of eclipsing binary star.
c. high-mass giant or supergiant star that pulsates regularly in size and brightness.
d. variable emission nebula near a T Tauri star.
c. high-mass giant or supergiant star that pulsates regularly in size and brightness.
What is the most important use of Cepheid variables for astronomers?

a. The metal content of a Cepheid variable can be found very easily.
b. The distance to a Cepheid variable can be found very easily.
c. The diameter of a Cepheid variable can be found very easily.
d. The characteristics of the pulsation of a Cepheid variable can be used to investigate conditions in the core of the star.
b. The distance to a Cepheid variable can be found very easily.
The period of variability of a Cepheid variable star, which is easily measured, is directly related to which stellar parameter, thereby providing a reliable method for the measurement of distance to stars?

a. Surface magnetic field
b. Surface temperature
c. Velocity away from Earth
d. Luminosity
d. Luminosity
RR Lyrae variables are likely to be found in:

a. young- to intermediate-age clusters, where high-mass stars are undergoing central helium burning.
b. very young clusters, where high-mass stars are undergoing core hydrogen burning.
c. giant molecular clouds, where protostars are forming from gas and dust clouds.
d. globular clusters, where low-mass stars are undergoing core helium burning.
d. globular clusters, where low-mass stars are undergoing core helium burning.
What are the stars in the upper part of the instability strip called?

a. Protostars
b. RR Lyrae variables
c. Cepheid variables
d. T Tauri stars
c. Cepheid variables
In a semi-detached binary star system:

a. the stars share the same outer atmosphere, but the cores of the two stars do not touch.
b. one star orbits the center of mass while the other moves freely off through space.
c. both stars fill their Roche lobes.
d. one star fills its Roche lobe while the other does not.
d. one star fills its Roche lobe while the other does not.
The shape of the cross-section of the Roche lobes around a close binary star system, taken through the centers of both stars, is:

a. an ellipse, with a star at each focus.
b. two unequal ellipses that touch at the center of the lobes.
c. a figure eight.
d. a sphere, centered on the center of mass of the star system.
c. a figure eight.
Which of the following objects does not represent the endpoint of a star's evolutionary life?

a. Neutron star
b. Black hole
c. Supernova
d. Red giant
d. Red giant
What are the main byproducts of helium nuclear "burning" in red giant stars?

a. Carbon and oxygen nuclei
b. Hydrogen nuclei
c. The helium is transformed completely to energy.
d. Iron nuclei
a. Carbon and oxygen nuclei
An asymptotic giant branch (AGB) star is a:

a. blue supergiant.
b. cool main sequence star.
c. star in its first red giant phase.
d. red supergiant.
d. red supergiant.
A planetary nebula is:

a. a gas cloud surrounding a planet after its formation.
b. a shell of ejected gases, glowing because of ultraviolet light from a dying central star.
c. the formation stages of planets around stars other than the Sun.
d. the spherical cloud of gas produced by a supernova explosion.
b. a shell of ejected gases, glowing because of ultraviolet light from a dying central star.
The typical diameter of a planetary nebula is:

b. only about 3 to 5 stellar diameters.
The fraction of the mass of a red giant that is ejected as a shell in a planetary nebula is:

a. almost the whole star, mostly greater than 90%.
b. substantial, up to 40% or more.
c. extremely small, less than 1 part in 104.
d. small, close to 0.01, or 1%.
b. substantial, up to 40% or more.
Stars that have ejected a planetary nebula go on to become:

a. supernovae.
b. white dwarfs.
c. red giants.
d. protostars.
b. white dwarfs.
A white dwarf star is about the same size as:

a. the Sun.
b. the total solar system.
c. New York City.
d. the Earth.
d. the Earth.
A white dwarf is generating its energy from what source?

a. Gravitational potential energy as the star slowly contracts
b. Nuclear fusion of heavy elements in the central core
c. Nuclear fusion of hydrogen into helium
d. It no longer generates energy, but cools slowly.
d. It no longer generates energy, but cools slowly.
The stars that eventually become white dwarfs are those that start life with masses of less than:

a. 3 solar masses.
b. 4 solar masses.
c. 25 solar masses.
d. 1.4 solar masses.
b. 4 solar masses.
There is a mass limit for a star in the white dwarf phase, the Chandrasekhar limit, beyond which the star can no longer support itself against its own weight. This mass limit, in terms of solar mass, is:

a. 1.4.
b. 14.
c. 30.
d. 0.2.
a. 1.4.
As a white dwarf evolves, the direction of its motion on the Herzsprung-Russell diagram is from upper left to lower right, which means that:

a. it heats up as it shrinks because of the release of gravitational energy, ending up as a very hot but very small star.
b. its size or radius slowly increases as it cools, until it ends up as a red giant star.
c. its size or radius remains constant as it cools and becomes less luminous.
d. it shrinks as it cools, eventually becoming a cold, black hole in space.
c. its size or radius remains constant as it cools and becomes less luminous.
White dwarf stars are supported from collapse by:

a. centrifugal force due to rapid rotation.
b. degenerate-electron pressure.
c. nuclear fusion reactions in their cores.
d. nuclear fusion reactions in a shell around the core.
b. degenerate-electron pressure.
A white dwarf is:

a. a low-mass star at the end of its life.
b. a type of protostar.
c. an object like Jupiter that was not massive enough to become a star.
d. a hot main sequence star.
a. a low-mass star at the end of its life.
In astronomical terms, planetary nebulae are:

a. relatively long lived, because they form when the original stars form and remain as slowly rotating shells for the whole of their lifetimes of several billion years.
b. relatively short lived, existing around the central white dwarf star for millions of years before slowly spreading into space.
c. very long lived, having been in existence since just after the Big Bang at the beginning of the Universe.
After the material in the core of a massive star has been converted to iron by thermonuclear reactions, further energy can be released to heat the core only by:

a. thermonuclear fusion of iron into heavier elements.
b. nuclear fission or splitting of nuclei.
c. the absorption of neutrinos.
d. gravitational contraction.
d. gravitational contraction.
The mass ejected as a shell in the remnant of a supernova explosion of a massive star is what fraction of its pre-explosion mass?

a. All, or almost all (0.96)
b. Only a small fraction, about 1/100
c. Between 1/4 and 1/2
d. Only the outer atmosphere, less than 1 part in 104
a. All, or almost all (0.96)
The star that exploded to form supernova SN1987A probably had, before it blew up, a mass of about:

a. 1.4 solar masses.
b. 40 to 50 solar masses.
c. less than one solar mass.
d. 20 solar masses.
d. 20 solar masses.
The supernova SN1987A differed from most other supernovae because:

a. it occurred in an external galaxy (not our Milky Way galaxy).
b. it reached a maximum luminosity ten times that of a normal supernova.
c. it declined in brightness much faster than most supernovae.
d. the star was a blue supergiant when it blew up, rather than a red supergiant.
d. the star was a blue supergiant when it blew up, rather than a red supergiant.
What new method has recently provided astronomers with new information about the behavior of stars beneath their surfaces (for example, the collapse of the inner core of a star undergoing supernova explosion, or the interior of the Sun)?

a. Neutrino astronomy
b. Visible light spectroscopy
d. X-ray astronomy and photography
a. Neutrino astronomy
Supernovae are detected:

a. only at X-ray wavelengths.
b. in both our Galaxy and others.
c. only in elliptical galaxies, never in spirals.
d. only in our Galaxy.
b. in both our Galaxy and others.
A Type II supernova is:

a. the explosion of a white dwarf in a binary star system after mass has been transferred onto it from its companion.
b. the collapse of a blue supergiant star to form a black hole.
c. the explosion of a red giant star as a result of helium flash in the core.
d. the explosion of a massive star after silicon burning has produced a core of iron nuclei.
d. the explosion of a massive star after silicon burning has produced a core of iron nuclei.
A Type 1a supernova is:

a. the collapse of a blue supergiant star to form a black hole.
b. the explosion of a white dwarf in a binary star system after mass has been transferred onto it from its companion.
c. the explosion of a massive star that has lost its hydrogen-rich outer layers through a stellar wind or mass transfer in a binary star.
d. the explosion of a massive star after silicon burning has produced a core of iron nuclei.
b. the explosion of a white dwarf in a binary star system after mass has been transferred onto it from its companion.
A Type Ib supernova is believed to result from:

a. the collapse of a blue supergiant star to form a black hole.
b. the explosion of a massive, hydrogen-rich star after silicon burning has produced a core of iron nuclei.
c. the explosion of a white dwarf in a binary star system after matter transferred onto it from its companion has increased its mass above the Chandrasekhar limit.
d. the explosion of a massive star that has lost its hydrogen-rich outer layers through a stellar wind or mass transfer in a binary star.
d. the explosion of a massive star that has lost its hydrogen-rich outer layers through a stellar wind or mass transfer in a binary star.
Type Ia supernovae can be used as distance indicators because:

a. hyperspace is continuous in the region of the explosion due to the Chandrasekhar limit.
b. all such supernovae have identical apparent magnitudes when examined through a telescope.
c. the distances to all Type Ia supernovae are already known.
d. there is a known relation between peak luminosity and the rate of light decline for Type Ia supernovae.
d. there is a known relation between peak luminosity and the rate of light decline for Type Ia supernovae.
The estimated rate at which supernovae occur in our Galaxy is about once every:

a. 20 years.
b. 300 years.
c. 5 years.
d. 3000 years.
a. 20 years.
Which major astronomical event was apparently recorded faithfully by Chinese astronomers in the Sung Dynasty in 1054 A.D.?

a. The passage of the planet Venus across the face of the Sun, a solar transit
b. The total eclipse of the Sun in that year
c. A supernova explosion in our Galaxy, visible even in daylight
d. The discovery of the planet Mercury
c. A supernova explosion in our Galaxy, visible even in daylight
The diameter of a typical neutron star of 1 solar mass is predicted to be approximately:

a. 1 km.
b. that of the Sun.
c. that of an average city, about 30 km.
d. that of Earth, 12,800 km.
c. that of an average city, about 30 km.
In what year was the first pulsar discovered?

a. 1978
b. 1967
c. 1960
d. 1930
b. 1967
A pulsar is:

a. a binary star in which matter from one star is falling onto the second star.
b. an object at the center of each galaxy, providing energy from its rapid rotation.
c. a pulsating star in which size, temperature, and light intensity vary regularly.
d. a rapidly rotating neutron star emitting beams of radio radiation and, in some cases, X-rays and visible light.
d. a rapidly rotating neutron star emitting beams of radio radiation and, in some cases, X-rays and visible light.

a. charged particles move at speeds faster than the speed of light in any medium.
b. matter and antimatter meet and annihilate.
c. charged particles are forced to move along curved paths within a magnetic field.
d. charged particles are accelerated in straight lines into dense gas such as the outer atmosphere of a star.
c. charged particles are forced to move along curved paths within a magnetic field.
The mechanism that gives rise to the phenomenon of the nova is:

a. the impact and subsequent explosion of a large comet nucleus upon a star's surface.
b. matter from a companion star falling onto a white dwarf in a close binary system, eventually causing a nuclear explosion on the dwarf's surface.
c. the complete disintegration of a massive star because of thermonuclear runaway in the star's interior.
d. material falling into a black hole and being condensed to the point where a thermonuclear explosion is produced.
b. matter from a companion star falling onto a white dwarf in a close binary system, eventually causing a nuclear explosion on the dwarf's surface.
What is "special" about the special theory of relativity?

a. It deals only with motion at speeds far less than the speed of light.
b. It deals with both constant motion and accelerated motion but excludes all other effects; in particular, it excludes gravity.
c. It deals only with objects moving in a straight line at constant speed.
d. It deals only with objects that are at rest relative to one another.
c. It deals only with objects moving in a straight line at constant speed.
Two rocket ships are traveling past the Earth at 90% of the speed of light, in opposite directions (that is, they are approaching each other). One ship turns on a searchlight beam that is seen by scientists aboard the other ship. What speed do the scientists measure for this light? (c = speed of light in a vacuum.)

a. 0.9c
b. 1.9c (equal to c + 0.9c)
c. 1.8c (equal to 2 x 0.9c)
d. c
d. c
Suppose a satellite were placed in orbit around (and very close to) a neutron star. Which theory would you need to use to describe how it moves?

a. The general theory of relativity
b. The special theory of relativity
c. Kepler's laws
d. Newton's theory of gravitation
a. The general theory of relativity
How does a gravitational field affect the passage of time?

a. Gravity has no effect on the passage of time.
b. Clocks in a gravitational field run faster than clocks outside the field.
c. Gravity makes time stop.
d. Clocks in a gravitational field run slower than clocks outside the field.
d. Clocks in a gravitational field run slower than clocks outside the field.
A black hole is so named because:

a. it emits no visible light because it is cold, its energy being held in an intense gravity field.
b. the gravitational field is so high that the wavelength of the emitted light is shifted into the infrared.
c. no light can escape from it due to its powerful gravitational field.
d. its spectrum has the same shape as that of a laboratory black body at a temperature of about 1000 K.
c. no light can escape from it due to its powerful gravitational field.
In a binary star system, an unseen component is found to have a mass of about 8 solar masses. If this were a normal star then it would be visible, so it must be a collapsed object. Theoretical considerations tell us that it must be a:

a. brown dwarf.
b. white dwarf.
c. neutron star.
d. black hole.
d. black hole.
Where would you look for an event horizon?

a. In the photosphere of a star (for example, the Sun)
b. At the edge of the visible Universe
c. In the magnetosphere of a neutron star
d. In a black hole
d. In a black hole
How does the diameter of a black hole (meaning the size of the event horizon) depend on the mass inside the black hole?

a. The greater the mass, the smaller the diameter.
b. The diameter does not depend on the mass.
c. The greater the mass, the greater the diameter up to the mass limit for a black hole; above that mass, the black hole collapses.
d. The greater the mass, the greater the diameter.
d. The greater the mass, the greater the diameter.
What would happen to the gravitational force upon the Earth if the Sun were to be replaced by a 1-solar-mass black hole?

a. It would double in strength.
b. It would remain as it is now.
c. It would become extremely high, sufficient to pull the Earth into it.
d. It would be much less because the gravitational field of a black hole only exists very close to it.
b. It would remain as it is now.
In terms of black holes, what is a wormhole?

a. A "tunnel" of undistorted space through an event horizon allowing objects to enter and leave a black hole without being torn apart
b. A direct connection from a black hole to another part of spacetime
c. A long, thin black hole created by unstable electric fields within the black hole
d. A hole through a solid object, such as a planet, created by the passage of a small black hole through the object
b. A direct connection from a black hole to another part of spacetime
X-rays that come from the vicinity of a black hole actually originate from:

a. relatively far away from the black hole, where matter is still relatively cool.
b. well inside the event horizon.
c. its exact center, or singularity.
d. just outside the event horizon, on the accretion disk.
d. just outside the event horizon, on the accretion disk.
How has the mass of the black hole candidate Cygnus X1 been estimated?

a. From the observed size and estimated density of the object
b. From the periodic wobble in its own X-ray spectrum
c. From the periodic wobble it produces in the spectral lines of its normal companion star
d. From the gravitational redshift, where the more massive the object the greater is the redshift of its spectral lines
c. From the periodic wobble it produces in the spectral lines of its normal companion star
Why is Cygnus X1 thought to be a black hole?

a. No light has ever been observed to come from it.
b. It is smaller than the Earth, but its mass is too large to be a neutron star or white dwarf.
c. It emits X-rays that flicker on time scales of a hundredth of a second.
d. It has pulled matter from its companion star into an accretion disk around itself.
b. It is smaller than the Earth, but its mass is too large to be a neutron star or white dwarf.
Suppose you are at the equator, which has a latitude of 0°. The altitude of the north celestial pole as seen from your position is:

a. 90°.
b. 66.5°.
c. 47°.
d. 23.5°.
e. 0°.
e. 0°.
Observation of the shift of a star's spectrum toward the red or blue enables us to determine the star's:

a. proper motion.
b. temperature.
d. distance.
e. spectral type.
Because of precession on the Earth, the:

a. solar day is longer than the sidereal day.
b. Sun moves north and south with the seasons.
c. celestial poles gradually change position among the stars.
d. stars rise earlier each night than the preceding night.
e. none of the above
c. celestial poles gradually change position among the stars.
Which kind of star has the greatest average density?

a. Red giant
b. Main sequence
c. White dwarf
d. Neutron star
e. Red supergiant
d. Neutron star
Which kind of process, as a net result, supplies the energy for the stars?

a. Energy is radiated through the release of gravitational potential energy.
b. Uranium splits to form lighter elements releasing energy through fission.
c. Helium is formed with cold fusion from hydrogen in a palladium lattice.
d. Hydrogen is converted to helium through fusion.
e. none of the above
d. Hydrogen is converted to helium through fusion.
Stars at the left-hand end of the main sequence have which one of these?

b. Large mass
c. Small size
d. Cool temperature
e. Red color
b. Large mass
Which of these is not a possible final stage of stellar evolution?

a. White dwarf
b. T Tauri stage
c. Black hole
d. Neutron star
e. Pulsar
b. T Tauri stage
The early experiments designed to search for solar neutrinos showed:

a. disagreement with general relativity.
b. that neutrinos do not exist.
c. that the Sun does not exist.
d. probable difficulty in our theories of stellar interiors.
e. agreement with theoretical predictions.
d. probable difficulty in our theories of stellar interiors.
Name the second most abundant element in typical stars.

a. Hydrogen
b. Oxygen
c. Calcium
d. Carbon
e. Helium
e. Helium
What characteristic is the same for all stars in a star cluster?

a. Mass
b. Color
c. Temperature
d. Age
e. Luminosity
d. Age
A good way to determine the distance of a distant star cluster is to:

a. compare its H-R diagram with a standard H-R diagram.
b. use parallax.
c. measure the radius of one of its stars and compare that with the angle the star subtends.
d. use the mass-luminosity relation.
e. measure it on a rocket ship odometer.
a. compare its H-R diagram with a standard H-R diagram.
Which of these features is not characteristic of nuclear fusion?

a. It is a plentiful energy source.
b. Four hydrogen atoms produce one helium atom (net result).
c. Neutrons and positrons are produced.
d. High temperature is needed to overcome electrostatic repulsion.
e. Very large, radioactive nuclei are produced as waste products.
e. Very large, radioactive nuclei are produced as waste products.
Which is not a characteristic of a red giant?

a. Nearly depleted hydrogen fuel in the core
b. Contracted stellar core
c. Iron being formed into heavier elements
d. Cool stellar exterior
e. Expansion of the outer layers of the stellar atmosphere
c. Iron being formed into heavier elements
How many stars of 7th magnitude in a small cluster would it take for the cluster to appear as bright as a single 1st magnitude star?

a. 10
b. 25
c. 100
d. 251
e. 1000
d. 251
The Crab nebula is material blown off a ____(15)____, which was observed by the Chinese in 1054 A.D. At its center we now observe a ____(16)____. (Fill in the appropriate letters.)

Line (15)
a. nova
b. black hole
c. supernova
d. star cluster
e. pulsar
f. white dwarf
g. Cepheid variable
h. planetary nebula
c. supernova
The Crab nebula is material blown off a ____(15)____, which was observed by the Chinese in 1054 A.D. At its center we now observe a ____(16)____. (Fill in the appropriate letters.)

Line (16)
a. nova
b. black hole
c. supernova
d. star cluster
e. pulsar
f. white dwarf
g. Cepheid variable
h. planetary nebula
e. pulsar
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star would you most likely classify as a red supergiant?
a. A
b. B
c. C
d. D
e. E
f. F
e. E
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star is the hottest?
a. A
b. B
c. C
d. D
e. E
f. F
f. F
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star is intrinsically the faintest?
a. A
b. B
c. C
d. D
e. E
f. F
a. A
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star appears the faintest in the night sky?
a. A
b. B
c. C
d. D
e. E
f. F
d. D
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star is the most distant?
a. A
b. B
c. C
d. D
e. E
f. F
d. D
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star is the closest?
a. A
b. B
c. C
d. D
e. E
f. F
a. A
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

In which star's spectrum are the hydrogen lines strongest?
a. A
b. B
c. C
d. D
e. E
f. F
b. B
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

Which star is the coolest?
a. A
b. B
c. C
d. D
e. E
f. F
e. E
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Absolute Magnitude:
1. 5
2. 1
3. -3
4. 3
5. -6
6. -4
Apparent Magnitude:
1. -1
2. 3
3. 5
4. 25
5. 10
6. 9
Spectral Type:
1. G2
2. A1
3. O4
4. F1
5. M2
6. O3

In which star's spectrum would you expect to see molecular bands?
a. A
b. B
c. C
d. D
e. E
f. F
e. E
In the 1790s, Sir William Herschel tried to measure the Sun's position in our Galaxy by:

a. counting the density of stars in different directions along the Milky Way.
b. comparing our Galaxy to photographs of the Andromeda galaxy.
c. measuring the locations of globular clusters around the Galaxy
d. measuring distances to star clusters and H II regions in the disk of the Galaxy.
a. counting the density of stars in different directions along the Milky Way.
When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be:

a. uniformly distributed throughout space, with no concentration in any area of the Milky Way.
b. spherically symmetric about a point in the constellation Sagittarius and concentrated in that direction.
c. concentrated in the plane of the Milky Way and clustered around the Sun's position, indicating that the Sun is close to the Galaxy's center.
d. in a relatively flat disk almost perpendicular to the plane of the Galaxy, with a relatively higher density of clusters toward its center.
b. spherically symmetric about a point in the constellation Sagittarius and concentrated in that direction.
The one component of the material of the Milky Way galaxy that prevents us from seeing and photographing the galactic center at optical wavelengths is:

a. very cold hydrogen gas.
b. the glare of light from nearby stars.
c. interstellar dust.
d. hot hydrogen gas.
c. interstellar dust.
Variable stars, such as Cepheid variables and RR Lyrae stars, are used in what important measurement in astronomy?

a. Surface temperature measurement
b. The keeping of accurate time
c. Rotation speeds of galaxies
d. Distance measurement
d. Distance measurement
The method used by Harlow Shapley in 1917 to estimate the Sun's location in our Galaxy was the measurement of the:

a. locations of globular clusters around the Galaxy.
b. density of stars in different directions along the Milky Way.
c. distances to open star clusters and H II regions in the disk of the Galaxy.
d. structure of the Andromeda galaxy and a comparison of this to the structure of our Galaxy.
a. locations of globular clusters around the Galaxy.
The diameter of our Galaxy is about:

a. 2 kpc
b. 160 kpc.
c. 8 kpc.
d. 49 kpc.
d. 49 kpc.
Where is the solar system located in our Galaxy?

a. It is not in a galaxy, but in intergalactic space.
b. In the galactic halo
c. In the galactic disk
d. In the galactic nucleus
c. In the galactic disk
Where are the majority of older, metal-poor stars found in our Galaxy?

a. Everywhere in the Galaxy
b. Only at the galactic center
c. In the disk and spiral arms
d. In the globular clusters in the galactic halo
d. In the globular clusters in the galactic halo
The Milky Way is an example of which type of galaxy?

a. Lenticular (S0)
b. Irregular
c. Spiral
d. Elliptical
c. Spiral
In our Galaxy, young metal-rich stars are found:

a. everywhere in the Galaxy.
b. only at the galactic center.
c. in the disk and spiral arms.
d. in the globular clusters, in the galactic halo.
c. in the disk and spiral arms.
Radio waves of 21cm wavelength originate from which component of the interstellar medium?

a. Molecular hydrogen
b. Neutral atomic hydrogen
c. Ionized atomic hydrogen
d. Carbon monoxide
b. Neutral atomic hydrogen
The spiral-arm structure of the Milky Way galaxy has been measured and evaluated most effectively by observations of:

a. globular clusters in the halo of the Galaxy.
b. Lyman UV radiation from hot hydrogen gas.
c. 21cm radiation from interstellar hydrogen and the positions of young stars.
d. Balmer emission lines of visible radiation from hydrogen.
c. 21cm radiation from interstellar hydrogen and the positions of young stars.
Which of the following components of the Galaxy best outline the spiral arms of the Galaxy?

a. Young O and B stars, dust, and gas
b. Globular clusters
c. Predominantly solar-type stars
d. White dwarf stars
a. Young O and B stars, dust, and gas
The time taken for the Sun to orbit the galactic center once in its motion in the Galaxy is

b. 2.2 million years.
c. 1.3 x 1011 years.
d. 220 million years.
d. 220 million years.
How is the mass of the Galaxy estimated?

a. By observing the bending of light from distant galaxies as it passes near the Milky Way center
b. By counting stars and assuming an average stellar mass
c. By observing its movement toward neighboring galaxies
d. By applying Newton's extension of Kepler's laws to the motion of the Sun and other stars
d. By applying Newton's extension of Kepler's laws to the motion of the Sun and other stars
The possible presence of a very large amount of unseen ("dark") matter in the halo of our Galaxy is deduced from:

a. the unexpected high amount of interstellar absorption in certain directions.
b. the unexpected absence of luminous matter (stars, and so forth) beyond a certain distance.
c. the rotation curve of our Galaxy, which shows that orbital speeds in the outer parts of the Galaxy decrease in a way that follows Kepler's law.
d. the rotation curve of our Galaxy, which indicates higher than expected orbital speeds in the outer regions of the Galaxy.
d. the rotation curve of our Galaxy, which indicates higher than expected orbital speeds in the outer regions of the Galaxy.
In which constellation in our sky is the center of our Milky Way galaxy located?

a. Sagittarius
b. Ursa Major
c. Hercules
d. Lyra
a. Sagittarius
The center of our Milky Way galaxy can be observed most easily at which of the following wavelengths?

a. Highly penetrating gamma rays
b. Ultraviolet light
c. Hydrogen Balmer Hα light
Which kinds of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae within the planes of the Milky Way and other galaxies?

a. Hot, young O and B stars, via their UV radiation
b. The numerous old, red giant K and M stars, via their IR heat radiation
c. Very hot white dwarf stars, the remnants of planetary nebulas in the gas clouds
d. The very many novae and supernovae explosions of stars within the gas and dust clouds
a. Hot, young O and B stars, via their UV radiation
What evidence now exists for a supermassive black hole at the center of our Galaxy?

a. Observations of intense inflow of matter toward the center of the Galaxy as seen by light, Doppler-shifted toward the red, emitted by this matter
b. A very dark void in an otherwise bright region of space near the galactic center, indicating the presence of a black hole
c. Very bright X-ray emissions from the galactic center
d. Very rapid motion of matter close to the nucleus of the Galaxy, requiring a very massive body to hold it in orbit
d. Very rapid motion of matter close to the nucleus of the Galaxy, requiring a very massive body to hold it in orbit
Which of the following absolute magnitudes is the brightest?

a. 5.0
b. 2.0
c. 0.0
d. -2.0
e. -5.0
d. -2.0
Which of the following spectral types is the hottest?

a. B5
b. O9
c. B1
d. A2
e. O7
b. O9
What is the single most important characteristic in determining the course of a star's evolution?

a. Absolute brightness
b. Distance
c. Surface temperature
d. Apparent magnitude
e. Mass
e. Mass
A nearby star has a parallax of 0.5 arc seconds. What is its distance?

a. 0.1 pc
b. 0.2 pc
c. 0.5 pc
d. 1 pc
e. 2 pc
e. 2 pc
What is the size of a typical white dwarf?

Which of the following stars has the greatest luminosity?

a. G5 III
b. B3 IV
c. G2 V
d. F7 1a
e. M3 II
d. F7 1a
What are the general characteristics of a typical galactic cluster of stars?

a. Old age and tens of thousands of stars
b. No main sequence stars and up to a million stars
c. A few hundred, mostly main sequence, stars
d. Large size and tens of thousands of stars
e. No main sequence and essentially no stars
c. A few hundred, mostly main sequence, stars
Interstellar gas is composed mainly of:

a. hydrogen and helium.
b. carbon.
c. ammonia, methane, and water vapor.
d. hydrogen and carbon.
e. neon.
a. hydrogen and helium.
Some regions of the Milky Way appear dark because:

a. there are no stars there.
b. stars in that direction are obscured by Zeeman splitting from magnetic fields.
c. stars in that direction are obscured by interstellar dust.
d. there are numerous black holes that capture all the starlight behind them.
e. stars in that direction are obscured by massive neutrinos that hinder the passage of light.
c. stars in that direction are obscured by interstellar dust.
Which two ingredients are needed to make an emission nebula?

a. Interstellar gas and dust
b. Cool stars and interstellar dust
c. Hot stars and interstellar gas
d. Cool stars and interstellar gas
e. Hot carbon strands for filaments
c. Hot stars and interstellar gas
A cloud fragment too small to form a star becomes a:

a. black hole.
b. brown dwarf.
c. Herbig-Haro object.
d. Bok globule.
e. carbonaceous chondrite.
b. brown dwarf.
At what stage of evolution do T Tauri stars occur?

a. Just as a cloud of material starts to collapse
b. Just prior to the collapse of a giant molecular cloud
c. When a protostar is on the verge of becoming a main sequence star
d. After the star has established itself as a post-main sequence star
e. Just after the horizontal branch stage
c. When a protostar is on the verge of becoming a main sequence star
Which of the following represents the last observed stage in the evolution of a low-mass star?

a. Red giant
b. Green giant
c. Planetary nebula
d. Brown dwarf
e. White dwarf
e. White dwarf
What is one of the major differences between Cepheid and RR Lyrae variables?

a. Cepheids are higher luminosity stars than RR Lyrae variables.
b. All Cepheids have the same luminosity.
c. RR Lyrae variables pulsate irregularly as compared to Cepheids, which are very regular.
d. Cepheids vary because they pulsate; RR Lyrae variables vary because they are binaries.
e. Only Cepheids are useful as distance indicators.
a. Cepheids are higher luminosity stars than RR Lyrae variables.
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

Which star has the greatest intrinsic brightness?
a. A
b. B
c. C
d. D
e. E
f. F
e. E
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

Which star appears the faintest?
a. A
b. B
c. C
d. D
e. E
f. F
d. D
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

Which star is the closest?
a. A
b. B
c. C
d. D
e. E
f. F
a. A
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

Which star has the greatest photospheric temperature?
a. A
b. B
c. C
d. D
e. E
f. F
f. F
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

In which star's spectrum would you expect to see molecular bands?
a. A
b. B
c. C
d. D
e. E
f. F
e. E
Star:
1. A
2. B
3. C
4. D
5. E
6. F
Apparent Magnitude:
1.-1
2.1
3. 5
4.25
5.10
6.9
Absolute Magnitude:
1.5
2.1
3.-3
4.3
5.-6
6.-4
Spectral Type:
1. G5
2. A2
3. O5
4. F3
5. M3
6. O4

Which star is exactly 10 parsecs away?
a. A
b. B
c. C
d. D
e. E
f. F
b. B
The famous Curtis-Shapley debate in 1920 concerned which fundamental astronomical question in astronomy?

a. Whether all stars were like the Sun, or fundamentally different
b. Whether the spiral "nebulae" were part of the Milky Way galaxy or more distant, separate entities
c. Whether the Universe was expanding outward in all directions
d. Whether the Sun was at the center of the Milky Way galaxy
b. Whether the spiral "nebulae" were part of the Milky Way galaxy or more distant, separate entities
The method used by Hubble to determine the distance to the Andromeda galaxy (M31), thereby establishing the concept of separate and individual galaxies throughout the Universe, was the:

a. measurement of the redshift of the whole Galaxy.
b. measurement of stellar parallax, or apparent motion of stars, because of Earth's orbital motion.
c. observation of Cepheid variable stars.
d. observation of the brightnesses of novae.
c. observation of Cepheid variable stars.
The typical diameter of a spiral galaxy is about:

a. 1 light year.
b. 10^7 light years.
c. 100 light years.
d. 10^5 light years.
d. 10^5 light years.
The Hubble classification for a spiral galaxy with a prominent central bulge and tightly wound spiral arms is:

a. E0.
b. Sa.
c. SBa.
d. Sc.
b. Sa.
The Hubble classification for a galaxy having loosely wound spiral arms originating at the ends of a bar through the central bulge is:

a. SBc.
b. Sb.
c. SBa.
d. S0.
a. SBc.
How does the number of barred spirals in the Universe compare to the number of ordinary spirals?

a. The question is meaningless; barred spirals are simply ordinary spirals seen edge-on.
b. There are about equal numbers of barred spirals and ordinary spirals.
c. Ordinary spirals outnumber barred spirals.
d. Barred spirals outnumber ordinary spirals.
d. Barred spirals outnumber ordinary spirals.
The Hubble classification for a galaxy with a circular outline and a smooth distribution of brightness is:

a. E0.
b. Sa.
c. Sc.
d. E7.
a. E0.
The Hubble classification for a very flat elliptical galaxy is:

a. E0.
b. Sc.
c. E7.
d. SBc.
c. E7.
There is little or no interstellar dust or gas in which of the following galaxy types?

a. Spirals
b. Barred spirals
c. Irregular galaxies
d. Ellipticals
d. Ellipticals
Which of the following types of galaxies contains primarily population II, low-mass, long lived stars?

a. Ellipticals
b. Irregular galaxies
c. Lenticular galaxies
d. Spirals
a. Ellipticals
Which are the largest galaxies in the Universe?

a. Irregular galaxies
b. Large spiral galaxies like the Milky Way galaxy
c. Lenticular galaxies
d. Giant elliptical galaxies
d. Giant elliptical galaxies
How are the Magellanic Clouds, the two nearby satellite galaxies of our own Galaxy, classified?

a. Irregular galaxies
b. Globular clusters
c. Elliptical galaxies
d. Spiral galaxies
a. Irregular galaxies
To an astronomer, what is a "standard candle"?

a. Any type of object whose absolute magnitude is known
b. Any galaxy whose redshift has been measured accurately
c. A standard light source that can be placed in a telescope, to which the brightnesses of stars and other objects can be compared
d. An accurately defined brightness scale for stars and galaxies, such as the magnitude scale
a. Any type of object whose absolute magnitude is known
In the 1970s it was discovered that among spiral galaxies, the wider the 21cm radio emission line, the brighter the galaxy. What name is given to this relation?

a. The Hubble law
b. The Tully-Fisher relation
c. The Schwarzschild law
d. The mass-luminosity relation
b. The Tully-Fisher relation
Who first discovered that the majority of galaxies are moving away from the Earth?

a. Edwin Hubble
b. Karl Jansky
c. V. M. Slipher
d. Albert Einstein
c. V. M. Slipher
Hubble's law describes how two quantities are related to each other. What are these two quantities?

a. Distance and brightness
b. Brightness and the width of the 21cm radio emission line of hydrogen
c. Distance and velocity of recession
d. Brightness and recession velocity
c. Distance and velocity of recession
What method is used to determine the distances of very remote galaxies?

a. Measurement of the apparent brightness and period of Cepheid variable stars within the galaxies
b. Comparison of their apparent and absolute magnitudes
c.Measurement of the angular size of the galaxy and an assumption about the actual physical size of the galaxy
d. Use of their spectral redshifts and the Hubble law
d. Use of their spectral redshifts and the Hubble law
The "Local Group" is:

a. the name of the spiral arm of our Galaxy in which the Sun is located.
b. the family of planets around the Sun.
c. a star cluster to which the Sun belongs.
d. a cluster of galaxies in which the Milky Way is located.
d. a cluster of galaxies in which the Milky Way is located.
What is the famous Virgo cluster of galaxies?

a. A rich, regular cluster of thousands of galaxies
b. The nearest cluster beyond the Local Group, with about three dozen galaxies in it
c. A cluster of unknown type centered on a quasar near the edge of the visible Universe
d. A rich, irregular cluster of more than 1000 galaxies
d. A rich, irregular cluster of more than 1000 galaxies
What is a supercluster of galaxies?

a. It is a cluster of galaxy clusters.
b. It is a phrase describing all the galaxies in the Universe as a single system.
c. It is a cluster of galaxies that is packed much more densely than normal clusters, giving it a significantly higher mass.
d. It is a cluster of galaxies that is spread out over a larger-than-normal volume of space.
a. It is a cluster of galaxy clusters.
One of the consequences of the collision of two galaxies appears to be:

a. a very large explosion, similar to but much larger than a supernova.
b. almost nothing, because stars are widely separated in each galaxy and the probability of star-star collisions is very small.
c. the disappearance of one of them into the central black hole of the other.
d. a burst of vigorous star birth.
d. a burst of vigorous star birth.
What is believed to be the origin of giant elliptical galaxies?

a. Collisions between galaxies in the cluster produce a smooth distribution of stars through the cluster; these sink to the cluster center and form giant elliptical galaxies.
b. They grew by devouring smaller galaxies.
c. They have grown continuously since their formation, by accreting intergalactic gas.
d. They formed that way and have remained unchanged ever since.
b. They grew by devouring smaller galaxies.
Which one of the following statements is true about clusters of galaxies?

a. The mass observed in the galaxies of the cluster is about 10 times too small to hold the cluster together.
b. The mass observed in the galaxies of the cluster is many thousands of times too small to hold the cluster together.
c. The mass observed in the galaxies of the cluster is typically almost exactly equal to that needed to hold the cluster together.
d. The mass observed in the galaxies of the cluster is about 10 times larger than the amount needed to hold the cluster together.
a. The mass observed in the galaxies of the cluster is about 10 times too small to hold the cluster together.
If most of the mass of a galaxy is located near the center of the galaxy, then in the outer part of this galaxy we would expect the orbital speeds of stars to decrease with increasing distance from the center. This is an example of:

a. Newton's third law.
b. Hubble's law.
c. Wien's law.
d.Kepler's third law.
d.Kepler's third law.
Dark, unknown forms of matter appear to make up about what fraction of the mass of a typical rich cluster of galaxies?

a. 10%
b. 90%
c. Much less than 1%
d. Half
b. 90%
Astronomy with a radio telescope was initiated by:

a. Marconi in Europe.
b. the National Science Foundation and the American Astronomical Society.
c. the British Broadcasting Corporation in England.
d. an amateur astronomer, Grote Reber, after Jansky detected radio energy from the Galaxy.
d. an amateur astronomer, Grote Reber, after Jansky detected radio energy from the Galaxy.
The discovery of the peculiar galaxy Cygnus A was a surprise to astronomers because it:

a. has a redshift as high as those of the most distant quasars.
b. is very faint at visible wavelengths but extremely bright at radio wavelengths.
c. was discovered first at X-ray wavelengths, only later being seen optically.
d. was so bright at optical wavelengths that no one expected it to be a galaxy.
b. is very faint at visible wavelengths but extremely bright at radio wavelengths.
Quasars appear to be:

a. very distant, intrinsically faint objects, moving toward Earth very rapidly.
b. relatively close, very bright objects moving away from Earth.
c. very distant, intrinsically bright objects, moving away from Earth at very high speeds.
d. very distant and intrinsically bright objects moving in random directions at high speeds.
c. very distant, intrinsically bright objects, moving away from Earth at very high speeds.
The typical optical spectrum of a quasar shows:

a. a series of very blueshifted emission lines, with no continuum component.
b. a sequence of highly blueshifted absorption lines upon a continuum of radiation.
c. a continuum of radiation crossed by a sequence of very redshifted absorption lines.
d. very redshifted emission lines superimposed upon a weak continuum of radiation.
d. very redshifted emission lines superimposed upon a weak continuum of radiation.
Astronomers initially had difficulty identifying the emission lines in quasar spectra at optical wavelengths because:

a. quasars are receding from us at extremely high speeds and this smears out the emission lines, making them hard to measure.
b. no one expected violet and ultraviolet spectral lines to be shifted so far toward the red.
c. the lines are created by elements that do not exist on Earth.
d. they were emission lines from ionized atoms that had not been seen before.
b. no one expected violet and ultraviolet spectral lines to be shifted so far toward the red.
The distance to the bright quasar 3C 273 is estimated to be:

a. just beyond our Milky Way.
b. 2 billion light years.
c. 20,000 light years.
d. 3 million light years.
b. 2 billion light years.
The energy output of a bright quasar is equivalent to:

a. that of the Milky Way galaxy.
b. 1000 bright galaxies.
c. 1000 times that of the Sun.
d. 10^6 solar-type stars.
b. 1000 bright galaxies.
An electron moving in a magnetic field in space is forced to follow a spiral pattern. As it does so, it will emit:

a. X-rays.
c. visible light, mostly blue in color.
d. nothing, because such electrons are in equilibrium.
A quasar is now thought to be:

a. a long-lived supernova explosion.
b. the central core of an active galaxy.
c. a nearby star, ejected with great violence out of a galaxy.
d. a very active, very distant star.
b. the central core of an active galaxy.
Seyfert galaxies are:

a. very small elliptical galaxies.
b. the largest galaxies in the Universe.
c. irregular galaxies seen from the southern hemisphere.
d. active galaxies with very bright, star-like nuclei.
d. active galaxies with very bright, star-like nuclei.
A radio galaxy is any galaxy that:

a. emits large amounts of energy from the whole galaxy at radio wavelengths.
b. has two lobes, one on each side of the galaxy, which emit synchrotron radiation at radio wavelengths.
c. is invisible at optical wavelengths (ordinary light), and is detected only at radio wavelengths.
d. has a bright, compact nucleus that emits large amounts of thermal energy at radio wavelengths.
b. has two lobes, one on each side of the galaxy, which emit synchrotron radiation at radio wavelengths.
Blazars or BL Lacertae objects are:

a. giant irregular galaxies that have neither spiral arms nor the smooth shape of elliptical galaxies.
b. active galaxies, most of whose energy is emitted by two widely spaced radio lobes.
c. elliptical galaxies whose nuclei resemble quasars.
d. spiral galaxies whose nuclei resemble quasars.
c. elliptical galaxies whose nuclei resemble quasars.
Relatively rapid fluctuations (within one day) in the electromagnetic output of quasars and blazars is an indication of:

a. the rapid rotation of the sources.
b. the relatively small size of the emitting regions.
c. objects moving in front of them, from our point of view.
d. their relative closeness to the Milky Way.
b. the relatively small size of the emitting regions.
The "central engine" of an active galaxy appears to be:

a. the violent merger of two galaxies, in which the collision throws out jets of matter along the rotation axis of the larger galaxy.
b. a supermassive black hole at the center of an accretion disk, with jets of material being ejected perpendicular to the disk.
c. supernova explosions in an extremely dense star cluster at the center of the galaxy.
d. stars falling into a supermassive black hole, their remnants being thrown out in all directions.
b. a supermassive black hole at the center of an accretion disk, with jets of material being ejected perpendicular to the disk.
If double radio sources, quasars, and blazars are considered to be the same basic object, why do they appear to us to have very different and distinct properties?

a. Because they are at different distances from us, and we see more detail and different properties on those that are closer to us
b. Because we are viewing them at different angles to the line of the double jets emitted from their cores
c. Because the relativistic particles in the double jets are different in each case; electrons in double radio sources, protons in quasars, and quarks in blazars
d. Because they are of different ages
b. Because we are viewing them at different angles to the line of the double jets emitted from their cores

a. "Why is the sky dark at night?"
b. "What is beyond the edge of the Universe?"
c. "How old is the Universe?"
d. "Where did the Universe come from?"
a. "Why is the sky dark at night?"
Which scientist discovered that the equations he had derived predicted an expanding Universe, then modified his equations to eliminate this expansion?

a. Albert Einstein
b. Edwin Hubble
c. Isaac Newton
d. Stephen Hawking
a. Albert Einstein
The Hubble law, representing observations of distant objects in the Universe, relates which two parameters?

a. The luminosity and position of stars in the Galaxy
b. The distance to a distant object and its recession velocity
c. The mass of an object and its luminosity
d. The mass of a distant object and its recession velocity
b. The distance to a distant object and its recession velocity
For which objects in the Universe has the Hubble relation been shown to hold experimentally?

a. Stars in the near neighborhood of the Sun, in our Galaxy
b. Galaxies in the Local Group, in the near vicinity of the Milky Way
c. Distant galaxies
d. Stars in the distant spiral arms of our Galaxy
c. Distant galaxies
What do cosmologists study?

a. The origin, structure, and evolution of the solar system
b. The formation, structure, and evolution of galaxies
c. The formation, structure, and evolution of stars
d.The origin, structure, and evolution of the Universe
d.The origin, structure, and evolution of the Universe
Where are we?

a. Off-center in an expanding universe, as shown by fact that the microwave radiation is a different temperature in one direction than in the opposite direction
b.At the exact center of an expanding universe, as shown by the universal expansion away from us in all directions
c. Near the edge of an expanding universe, as shown by the Great Wall of Galaxies
d. Somewhere in an expanding universe, but not in any special part of it
d. Somewhere in an expanding universe, but not in any special part of it
Good evidence for an original Big Bang that "created" our Universe comes from:

a. the rapid motions of some nearby stars, such as Barnard's Star.
b. the measurement of the rotation of our Galaxy.
c. the amount of gas and dust in the solar neighborhood.
d. a background "glow" of microwaves, with blackbody temperature of about 3 K.
d. a background "glow" of microwaves, with blackbody temperature of about 3 K.
The cosmic background radiation is the:

a. result of the radioactive decay of heavier, unstable elements produced in supernova explosions.
b. faint glow along the ecliptic, caused by sunlight scattering from dust particles.
c. electromagnetic remnants of the explosion in which the Universe was born.
d. radio noise caused by high energy atomic nuclei known as cosmic rays, moving through magnetic fields in space.
c. electromagnetic remnants of the explosion in which the Universe was born.
What was the COBE satellite designed to measure?

a. The cosmic microwave background radiation
c. X-rays from quasars and other objects at cosmological distances
d. Redshifts of objects at cosmological distances, to obtain an accurate measurement of Hubble's constant
a. The cosmic microwave background radiation
Which of the following statements does not correctly describe the Universe at the era of recombination?

a. The Universe became transparent to radiation.
b. The temperature of the Universe was about 3 K
c. The Universe was about 300,000 years old.
d. Electrons and protons combined to form neutral hydrogen atoms.
b. The temperature of the Universe was about 3 K
Match the bright star with the constellations in which they belong.

Procyon
a. Gemini
b. Canis Minor
c. Canis Major
d. Orion
e. Leo
b. Canis Minor
Match the bright star with the constellations in which they belong.

Pollux
a. Gemini
b. Canis Minor
c. Canis Major
d. Orion
e. Leo
a. Gemini
Match the bright star with the constellations in which they belong.

Rigel
a. Gemini
b. Canis Minor
c. Canis Major
d. Orion
e. Leo
d. Orion
Match the bright star with the constellations in which they belong.

Regulus
a. Gemini
b. Canis Minor
c. Canis Major
d. Orion
e. Leo
e. Leo
How many astronomical units are there between the Earth and Sun?

a. One
b. Eight
c. Ten
d. One million
e. Six trillion
a. One
Of the following distances, which is the greatest?

a. 1,000,000,000 nanometers
b. One parsec
c. 100,000 astronomical units
d. The distance to the nearest star beyond the Sun
e. 3 light years
d. The distance to the nearest star beyond the Sun
What major contribution did Isaac Newton make to astronomy?

a. He discovered that the planets move around the Sun in elliptical orbits.
b. He developed a theory of gravity that could explain orbital motion.
c. He started the peer review system for publication of results.
d. He used a telescope to observe the heavens, thereby reinforcing the notion of heliocentricity.
e. He made extensive and detailed observations of the surfaces of the planets.
b. He developed a theory of gravity that could explain orbital motion.
If you view the spectrum of a typical nebula, what sort of spectrum are you likely to observe?

a. Continuous
b. Binary
c. Absorption
d. No spectrum will be visible.
e. Bright line
e. Bright line
Jupiter is noticeably oblate (you know this means flattened or non-spherical!) because it:

a. has a strong magnetic field.
b. has such powerful gravity.
c. rotates rapidly.
d. undergoes a gravitational attraction from each of its various moons.
e. is really a brown dwarf.
c. rotates rapidly.
What physical property is the same for all stars of spectral type F9?

a. Luminosity
b. Temperature
d. Mass
e. Composition
b. Temperature
A two-solar-mass protostar is just about to move onto the main sequence. This star will most likely have a main sequence spectral type of:

a. F.
b. G.
c. K.
d. M.
e. P.
a. F.
Who discovered the first object that eventually became known as a pulsar?

a. Jocelyn Bell
b. Anne Cannon
c. Martin Schwarzchild
d. Stephen Hawking
e. Henrietta Leavitt
a. Jocelyn Bell
Which of the following is not found in the Galaxy's spiral arms?

a. Young star clusters
b. O and B stars
c. Globular clusters
d. Emission nebulae
e. Dust lanes
c. Globular clusters
One of the consequences of the collision of two galaxies appears to be:

a. one galaxy falling into the central black hole of the other.
b. radiation levels that would make life impossible.
c. a large number of stars that collide and explode.
d. impossible; this can never occur.
e. a burst of vigorous star birth.
e. a burst of vigorous star birth.
What does the Hubble Law measure?

a. The rate of expansion of the Universe
b.How galaxies are distributed in the Universe
c. How light gets fainter with increasing distance
d. How light travels at a finite speed; we see objects the way they were when the light left them, not the way they are when we make our observations
e.The angular inverse of synchrotron radiation
a. The rate of expansion of the Universe
A galaxy is at a distance of one billion light years. Which of the following is true?

a. We see the galaxy the way it will be in one billion years.
b. We see the galaxy the way it was one billion years ago.
c. We see the galaxy the way it was when the Universe was one billion years old.
d. We see what our Galaxy will be like in one billion years.
e. We cannot see galaxies even close to this distance!
b. We see the galaxy the way it was one billion years ago.
From the Sun, what is the distance to the Galaxy's center?

a. 26 ly
b. 260 ly
c. 2,600 ly
d. 26,000 ly
e. It is impossible to estimate this distance.
d. 26,000 ly
Which of the following is not one of the Hubble types of galaxy?

a. Spiral
b. Irregular
c. Disk
d. Elliptical
e. Barred spiral
c. Disk
What is the classification given to a galaxy with a small nuclear bulge and loosely wound arms starting from a bar through the nuclear bulge?

a. S0
b. SBc
c. SBa
d. SBz
e. Sb
b. SBc
What type of variable star is generally used to determine the distances to globular clusters?

a. T Tauri
c. Omicron Ceti
d. Cepheids
e. RR Lyrae stars
e. RR Lyrae stars
What will happen if the Universe is unbounded?

a. The Universe will eventually fall back in on itself, heading toward a "Big Crunch."
b. The Universe will reach a maximum size and stay there, like a balloon that has been blown up.
c. The Universe will expand to its maximum size and then fragment into mini-universes.
d. The Universe will expand forever.
d. The Universe will expand forever.
In cosmology, the phrase "critical density" refers to the:

a. density above which the Universe is opaque to radiation.
b. density below which stars will never form.
c. smallest density that will produce inflation.
d. density needed to produce precisely flat space.
d. density needed to produce precisely flat space.
If space is flat, what is the future of the Universe?

a. It will expand to a maximum size and then collapse into a "Big Crunch."
b. The future of the Universe is not related to the geometry of space.
c. It will expand forever, not stopping even after infinite time.
d. It will barely expand forever, reaching zero expansion speed after infinite time.
d. It will barely expand forever, reaching zero expansion speed after infinite time.
The flatness problem in cosmology asks the question:

a. Why is the sky dark at night?
b. Why is temperature of the cosmic background radiation so smooth (isotropic) around the sky?
c. Why was the density of the Universe so close to the critical density just after the Big Bang?
d. Why are the four forces (strong, weak, electromagnetic, and gravitational) not unified in the present-day Universe?
b. Why is temperature of the cosmic background radiation so smooth (isotropic) around the sky?
In cosmology, what is the "inflationary epoch"?

a. The period of universal expansion from the Big Bang to the present
b. The first 300,000 years of the life of the Universe, when matter and radiation interacted vigorously
c. A period when the cost of living rose faster than astronomers' pay
d. A short period of extremely rapid expansion when the Universe was very young
d. A short period of extremely rapid expansion when the Universe was very young
In high-energy physics, when two gamma-ray photons meet, they can:

a. disappear, creating two negative electrons.
b. produce a huge number of low-energy photons.
c. disappear completely, leaving nothing behind.
d. disappear, creating a particle-antiparticle pair.
d. disappear, creating a particle-antiparticle pair.
Which elements were created during the Big Bang?

a. Only hydrogen
b. Hydrogen, helium, and lithium
c. Hydrogen, helium, lithium, and beryllium
d. Hydrogen and helium
c. Hydrogen, helium, lithium, and beryllium
How many fundamental forces are known in science?
a. Five
b. Four
c. Six
d. Three
b. Four
In modern particle physics, the proton and the neutron are now thought to be composed of more fundamental particles called:

a. gluons.
b. photons.
c. quarks.
d. neutrinos.
c. quarks.
At what speed will the neutrino travel if it is shown to have a small mass?

a. Less than the speed of light, c.
b. Since it will be a particle with mass, its speed will be governed by the temperature of its surroundings because it will always be in thermal equilibrium.
c. Faster than the speed of light, because this is the only way that it can have mass
d. Because of its nature, it can exist only when it is traveling at the speed of light, just like photons of electromagnetic radiation.
a. Less than the speed of light, c.
To what do the letters SETI refer?

b. Search for evidence of terrestrial-planet inhabitants
c. Sourcebook of extrasensory transient incidents
d. Search for extraterrestrial intelligence
d. Search for extraterrestrial intelligence
Which type of meteorite has been found to contain large organic molecules that make up the building blocks of life and provide strong evidence for their extraterrestrial production?

a. Iron
b. Stony-iron
c. Stony
d. Carbonaceous chondrite
d. Carbonaceous chondrite
The method used in the Urey-Miller experiment:

a. was to pass an electric arc through a mixture of hydrogen, ammonia, methane, and water, and then look for organic compounds.
b. was to attach a metal plaque to the Voyager spacecraft to tell extraterrestrial beings about us, if they ever find the spacecraft.
c. is to send radio signals using a pulsed code toward nearby stars that are similar to the Sun and may have planets.
d. is to monitor tens of millions of frequencies at once in an effort to detect extraterrestrial radio communications.
a. was to pass an electric arc through a mixture of hydrogen, ammonia, methane, and water, and then look for organic compounds.
In what way was the discovery of pulsars initially misinterpreted as evidence of intelligent life elsewhere in the Universe?

a. It was not thought possible for a "natural" source to produce the rapid and extremely regular radio pulses detected from space.
b. The rate of pulses detected from space appeared to contain primitive coding similar to a crude Morse code.
c. Radio telescopes occasionally detected the same sequence of five musical notes that were then whistled or hummed regularly by all the people associated with these telescopes.
d.Pulses arriving from several nearby star systems showed Doppler shifts of frequency apparently caused by orbital motion of their source around the central stars, as if coming from planets.
a. It was not thought possible for a "natural" source to produce the rapid and extremely regular radio pulses detected from space.
The first person to look for signals from extraterrestrial civilizations was:

a. Frank Drake.
b. Martin Schwarzschild.
c. Arno Penzias.
d. Jocelyn Bell.
a. Frank Drake.
The first search for radio signals from extraterrestrial civilizations was made in:

a. 1973.
b. 1948.
c. 1995.
d. 1960.
d. 1960.
The Drake equation attempts to predict the:

a. number of intelligent civilizations in the Universe.
b. number of technologically advanced civilizations in our Galaxy.
c. probability of primitive life existing elsewhere in our Galaxy.
d. number of inhabitable planets around stars in our Galaxy.
b. number of technologically advanced civilizations in our Galaxy.
Around which types of stars are we most likely to find planets supporting our kind of life forms?

a. Low-mass main sequence stars
b. Red giant stars
c. Very low-mass stars
d. High-mass main sequence stars
a. Low-mass main sequence stars
Most searches of space for evidence of intelligent life concentrate on radio wavelengths because:

a. it is likely that extraterrestrial beings will have developed radio transmitters before more complex lasers or IR light transmitters.
b. radio energy is least affected by dust and gas in the interstellar medium.
c.our atmosphere is most transparent at these wavelengths, and such signals will be more easily detected from Earth.
d.radio signals can carry the greatest amount of information per unit of time, so information transfer will be most efficient at these wavelengths.
b. radio energy is least affected by dust and gas in the interstellar medium.
The "water hole," a region of the radio spectrum chosen for searches for signals from intelligent life because galactic and Earth-based noise and atmospheric absorption are at a minimum, is so named because:

a. two astronomically important wavelengths, the 21-cm line of H and a line from the hydroxyl radical OH, are in this region (the letters H and OH signifying water).
b. water vapor absorption in our atmosphere reaches a sharp minimum at this wavelength.
c. water vapor emissions from planets at this wavelength will be a good indicator of life on other planets, because water is essential for life as we know it.
d. water vapor, H2O, has an intense laserlike emission line at this wavelength that extraterrestrials might use for communication.
a. two astronomically important wavelengths, the 21-cm line of H and a line from the hydroxyl radical OH, are in this region (the letters H and OH signifying water).
The constellations that are visible in the early evening gradually change throughout one year due to the:

a. rotation of the Earth.
b. precession of the Earth.
c. revolution of the Earth about the Sun.
d. elliptical shape of the Earth's orbit.
e. obliquity of the ecliptic.
c. revolution of the Earth about the Sun.
On March 21, the right ascension of the Sun is about:

a. 0 hours.
b. 6 hours.
c. 12 hours.
d. 18 hours.
e. 24 hours.
a. 0 hours.
The Ptolemaic system accounts for retrograde motion by:

a. placing the Sun at the center of the solar system.
b. placing the Earth at the center of the solar system.
c. having the planets move along the Tropic of Cancer.
d. having the planets travel on epicycles.
e. having the planets reverse their orbit.
d. having the planets travel on epicycles.
The ancients thought that rest (i.e., no motion) was the natural state for a material body. Newton's ________ law states that uniform linear motion is just as natural as rest.

a. first
b. second
c. third
d. fourth
e. gravitation
a. first
Galileo discovered all of the following except:

a. the phases of Venus.
b. stars too faint for the naked eye to see.
c. sunspots.
d. the planet Uranus.
e. the four largest satellites of Jupiter.
d. the planet Uranus.
If a telescope with an objective lens of three-foot focal length is used with an eyepiece of 1/4 inch focal length, the resulting magnification will be:

a. 12x.
b. 36x.
c. 48x.
d. 72x.
e. 144x.
e. 144x.
The law of universal gravitation was developed by:

a. Karnak.
b. Copernicus.
c. Tycho.
d. Galileo.
e. Newton.
e. Newton.
The gravitational attraction between two bodies depends on the distance, r, between them. The attraction varies with the distance as:

a. 1/r.
b.1/r^2.
c. r.
d. r^2.
b.1/r^2.
Ultraviolet radiation is of ________ than red light.

a. lower frequency and longer wavelength
b. higher frequency and longer wavelength
c. lower frequency and shorter wavelength
d. higher frequency and shorter wavelength
d. higher frequency and shorter wavelength
Boston is 90° east of Hawaii. If it is noon in Hawaii, in Boston it would be about:

a. sunrise.
b. sunset.
c. noon.
d. midnight.
e. noon the next day.
b. sunset.
The North Star does not appear to move during the night because:

a. the stars are fixed relative to each other.
b. it lies approximately over the northern axis of the Earth.
c.it is too nearby for its motion to be discernible.
d. it is located directly overhead for everyone on Earth.
b. it lies approximately over the northern axis of the Earth.
Of the following types of radiation, which has the smallest (i.e., the least energetic) photons or quanta?

a. Violet light
b. Infrared
d. Red light
e. X-rays
If an object is moving toward you, what effect do you observe in the spectrum of that object?

a. It appears redshifted.
b. The light appears to be moving faster.
c. All the spectral lines appear broadened.
d. It appears blueshifted.
e. The light appears brighter.
d. It appears blueshifted.
For what is an interferometer used?

a. To decrease the effects of atmospheric seeing for optical telescopes
b. To decrease the effects of light pollution in the images
c. To increase the sensitivity of infrared telescopes
d. To improve the angular resolution of radio telescopes
e. To process images from a CCD
d. To improve the angular resolution of radio telescopes
What do all kinds of electromagnetic (i.e., radiant) energy have in common?

a. All have the same frequency
b. All have the same wavelength
c. All have the same speed in a vacuum
d. All have photons of the same energy
e. All are observed in the same way
c. All have the same speed in a vacuum
Which of these is the greatest distance?

a. One lightyear
b. One parsec
c. One billion miles
d. The distance from the Earth to the Sun
e. The distance out to the orbit of the dwarf planet Pluto
b. One parsec
Beyond 100 parsecs, the distances determined by the method of trigonometric parallaxes become very unreliable because:

a. all stars that far away are too faint to measure accurately.
b. the parallax angles become too small to measure accurately.
c. stars that distant are so numerous that they are difficult to tell apart.
d. the proper motion of distant stars is so large that it masks the effect of parallax.
b. the parallax angles become too small to measure accurately.
How do the escape velocities of the Jovian planets compare to those of the terrestrial planets?

a. The Jovian planets have much higher escape velocities.
b. There is little variation among the planets.
c. The escape velocities vary greatly from planet to planet, but there are no general differences between Jovian and terrestrial planets.
d. The terrestrial planets have higher escape velocities.
a. The Jovian planets have much higher escape velocities.
What do we learn from the Doppler shift when we observe the spectrum of a star?

a. The star's distance
b. The star's proper motion
d. The star's temperature
e. The density of the star
Would the Moon be a good place to do astronomy?

a.No, because it is too close to the Earth and light reflected from the Earth interferes with the darkness of the lunar skies.
b. Yes, because the Moon lacks an atmosphere.
c.No, because people cannot survive for long on the Moon.
d. Yes, because lunar soil contains glass, which is useful in the construction of telescope mirrors.
b. Yes, because the Moon lacks an atmosphere.
How many stars of the sixth magnitude would equal the brightness of a star of the first magnitude?

a. 6
b. 10
c. 60
d. 100
e. 600
d. 100
Ten parsecs is the standard distance that has been selected as the basis for defining the astronomical scale of:

a. distances.
b. parallaxes.
c. spectral types.
d. space velocities.
e. absolute magnitudes.
e. absolute magnitudes.
All eclipsing binaries are also:

a. visual binaries.
b. optical doubles.
c. Cepheid variables.
d. spectroscopic binaries.
e. single stars.
d. spectroscopic binaries.
The differences in stellar spectra are due primarily to differences in:

a. chemical composition.
b. density.
c. velocity.
d.temperature.
e. viscosity.
d.temperature.
All stars of spectral type G2 have approximately the same:

a. temperature.
b. distance.
d. velocity.
e. age.
a. temperature.
Why does a star of type G5 have many absorption lines in its spectrum due to metallic elements such as iron, silicon, titanium, etc., while a star of type B5 shows very few lines of such elements?

a. They have different chemical compositions.
b. The B star is so cool that the metallic atoms are not vaporized and therefore cannot absorb light.
c. The B star is very hot and nearly all of its metallic atoms are ionized, which makes them incapable of absorbing photons having visible wavelengths.
d. The temperature of a G-type star is such that the metallic elements tend to concentrate near the stellar surface, making their spectral lines strong.
c. The B star is very hot and nearly all of its metallic atoms are ionized, which makes them incapable of absorbing photons having visible wavelengths.
A star with a spectral type of B2V would be referred to as which of the following?

a. Lower main sequence
b. Red supergiant
c. Upper main sequence
d. Blue supergiant
e. Red giant
c. Upper main sequence
What would Jupiter have needed to have become a star?

b. More mass
c. A slower rotation, like the Sun
d. A different chemical composition
b. More mass
A star that shows evidence of molecules in its spectrum would be considered:

a. very cool.
b. moderately cool (like the Sun).
c. average.
d. very hot.
e. moderately hot (like Vega).
a. very cool.
When the Moon is at third quarter, what time will it rise?

a. Noon
b. 6:00 p.m.
c. 6:00 a.m.
d. Midnight
d. Midnight
The minor planets (asteroids) in general follow orbits that lie between the orbits of:

a. Venus and Earth.
b. Earth and Mars.
c. Mars and Jupiter.
d. Jupiter and Saturn.
e. Neptune and Pluto.
c. Mars and Jupiter.
"Conservation of angular momentum" means that a spinning body tends to:

a. slow down.
b. veer into an eccentric orbit.
c. collapse due to the force of gravity.
d. keep spinning.
e. roll through space.
d. keep spinning.
The Sun rotates once in approximately one:

a. day.
b. week.
c. month.
d. year.
e. century.
c. month.
A given meteor shower, like the Leonids:

a. is visible on approximately the same date each year.
b. cannot be predicted.
c. is visible at various times throughout the years.
d.only occurs once.
a. is visible on approximately the same date each year.
In general, the tail of a comet streams away from the comet in a direction:

a. fixed by the galactic plane.
b. toward the Sun.
c. away from the Sun.
d. parallel to the comet's orbit.
e. constrained by the ecliptic plane.
c. away from the Sun.
The so-called "cosmological principle" is simply the idea that the basic large-scale features of the Universe:

a. depend upon the position of the observer.
b. depend upon the velocity of the observer.
c. are the same at all times past or future.
d. are the same regardless of location.
e. are different at the center of the Universe than at other locations.
d. are the same regardless of location.
All of the following may be used to estimate the solar surface temperature except:

a. Wein's law.
b. Kepler's laws.
c. the Stefan-Boltzman law.
d. Planck's law.
b. Kepler's laws.
Which of the following spectral types is the hottest?

a. G8
b. G9
c. F1
d. F2
e. F3
c. F1
Sunspots are associated with distortions in the Sun's:

a. gravitational field.
b. electric field.
c. magnetic field.
d. corn field.
e. visual field.
c. magnetic field.
One wavelength that may provide contact with extraterrestrial civilizations is found at:

a. 21 cm.
b. 1.34 s/km.
c. 3° K.
d. 3 x 10^8 m/s.
e. 22.7 HJM.
a. 21 cm.
Which of the following are not intrinsic variable stars?

a. Novae
b. RR Lyraes
c. Cepheids
d. Eclipsing variables
e. Miras
d. Eclipsing variables
Suppose that in the spectrum of a star the spectral lines are observed to be alternately single and then double in a periodic fashion. The star is probably:

a. near the galactic center.
b. a nova.
c. a spectroscopic binary.
d. a white dwarf.
e. an optical double.
c. a spectroscopic binary.
Of the many complex molecules found in interstellar space, most are based on which element?

a. Hydrogen
b. Silicon
c. Oxygen
d. Carbon
e. Uranium
d. Carbon
The "helium flash" occurs at what stage in stellar evolution?

a. In the middle of the main sequence stage
b. Red giant
c. Horizontal branch
d. Planetary nebula
e. Supergiant
b. Red giant
The absolute magnitude of the Sun is about:

a. -27.
b. +1.
c. +3.
d. +5.
e. +27.
d. +5.
The type of intrinsic variable stars often found in globular clusters are known as ________ stars.

a. Blue giant
b. T Tauri
c. Eclipsing binary
d.RR Lyrae
e. Novae
d.RR Lyrae
Cepheid variable stars are useful as distance indicators because they show a definite, simple correlation between their period of light variation and their:

a. distance.
b. average apparent magnitude.
c. average absolute magnitude.
d. spectral type.
c. average absolute magnitude.
The observed slowing of a clock in the vicinity of a black hole is a prediction of:

a. special relativity.
b. general relativity.
c. stellar nucleosynthesis.
d. the Principle of Cosmic Censorship.
b. general relativity.
Globular clusters:

a. are fairly evenly distributed in the sky as seen from the Earth.
b. are concentrated in the galactic plane.
c. are a special type of galaxy.
d. form a halo concentric with the center of our Galaxy.
e. contain only young stars.
d. form a halo concentric with the center of our Galaxy.
The Pleiades cluster of stars is an excellent example of a:

a. galactic or open cluster.
b. globular cluster.
c. KM association.
d. None of the above
a. galactic or open cluster.
The time required for a photon to travel across our Galaxy is about _____ years.

a. 1,600
b. 16,000
c. 160,000
d. 1,600,000
e. 1,600,000,000
c. 160,000
A star that is responsible for causing a nebula to fluoresce (i.e., emit an emission spectrum) is most likely a star of type:

a. A or F.
b.E.
c.K.
d. G.
e. O or B.
e. O or B.
What two observations of an object allow for a determination of the Milky Way's mass?

a. An object's mass and velocity
b. An object's age and distance from the galactic center
c. An object's mass and age
d. An object's velocity and distance from the galactic center
d. An object's velocity and distance from the galactic center
In the Drake equation, a technical civilization is considered to be:

a. a civilization that can communicate over interstellar distances.
b. a civilization that has the ability to store information.
c. a civilization that has developed interplanetary space travel.
d. a civilization that can construct tools out of raw materials.
e. life-forms that have developed the ability to communicate among themselves.
a. a civilization that can communicate over interstellar distances.
Which of the following are not found in the Galaxy's spiral arms?

a. Young star clusters
b. O and B stars
c. Globular clusters
d. Emission nebulae
e. Dust lanes
c. Globular clusters
A galaxy is at a distance of one billion light years. Which of the following is true?

a. We see the galaxy the way it will be in one billion years.
b. We see the galaxy the way it was one billion years ago.
c.We see the galaxy the way it was when the Universe was one billion years old.
d. We see what our Galaxy will be like in one billion years.
b. We see the galaxy the way it was one billion years ago.
Which type of galaxy has a stellar disk, but without gas or dust?

a. S0
b. Sc
c. Sa
d. SBa
e. Sb
a. S0
Shapley found that the nucleus (or center) of our Galaxy is located in the direction of the constellation:

a. Auriga.
b. Cygnus.
c. Sagittarius.
d. Orion.
e. Musca.
c. Sagittarius.
Quasars have their distances measured by what technique?

a. Cepheids
b. Tully-Fisher relation
c. Supernovae
d. Parallax
e. Hubble Law
e. Hubble Law
Pair production can occur if:

a. the energy of two photons is greater than the combined mass-energy of a particle-antiparticle pair.
b. only virtual particles are produced.
c.photons are at the event horizon of a black hole.
d. one particle is struck by a sufficiently high-energy photon to cause the formation of a pair of electrons.
a. the energy of two photons is greater than the combined mass-energy of a particle-antiparticle pair.