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When we observe a galaxy 10 LY away,

we see it as it was a billion years ago

Ages of stars are

NOT "millions of light years"

A wavelength of 10 microns is

in the infrared part of the spectrum

By measuring the light intensity from a distant light bulb, you can calculate its distance if you know the bulb's


In astronomy we try to

catalog objects and determine their origin

A hypothesis that passes initial testing

is ranked as a theory

An emission line with a wavelength of 6563 angstroms is


The most energetic photon is


According to the Stephen-Boltzmann Law, if the sun were twice as hot as it is,

it would be 16 times more luminous

The sun has

a absorption-line spectrum

In a hydrogen atom,

the proton has the most mass

A star with a surface temp of 10^4 K would be

bluer than the sun

A line in the Balmer series of hydrogen is


Red shifts in wavelength are produced by


The surface temp of the sun is about

5800 K

The light-gathering power of a telescope is proportional to its


Both Newtonian and Cassegrain telescopes

use 2 mirrors

Interferometers have

better angular resolution than ordinary telescopes

Spectrometers have


If the sin is setting and the moon is rising,

the moon is in the full phase

To see a total solar eclipse, you must be in the


How long a star is above the horizon depends on its


Precession takes about

26000 years

Some stars have

negative apparent magnitudes

The declination of Polaris is about

90 degrees

Fayetteville is at a latitude of about

36 degrees

In Grenwich, England, it is

later in the day now than it is in Fayetteville

The ecliptic is a projection of

the Earth's orbital plane

In Fayetteville at noon, the sun is farthest south in the


Planets usually move

west-to-east relative to the fixed stars

In Ptolemy's model

the planets orbited the Earth

Can stellar parallax be measured these days?

yes, but hey are less than an arc second

The moons of Jupiter were discovered by


The F=ma law was discovered by


Unlike Kepler's 3rd law, Newton's result contained


The plane of the orbits of the planets is a remnant of

the spin of the gas and dust cloud that spawned them

When we observe an object 10 billion light years away, we see it

as it was in the past

A photon of wavelength 5500 Å is in

the visible part of the spectrum.

My body emits mainly

infrared radiation

Blue photons carry

more energy than red photons

Wavelengths observed by ground-based telescopes are

limited by the atmosphere

The sun has

its peak wavelength in the visible

A light bulb radiates

a continuous spectrum

In the Bohr model downward transitions produce

emission lines

The Doppler effect measures

the radial component of the velocity

The boiling point of water in K is


In a telescope, the objective

gathers the light

The resolution of ground-based telescopes is limited to about 2 arcsec because

the "seeing" effects

A spectrogram may be displayed in the form of a graph of

intensity and wavelength

Lunar eclipses only happen when the moon is


Lunar eclipses can only happen during

during eclipse season

From the Earth's equator, the North Celestial Pole is

on the Northern horizon

The Sun appears to move

along ecliptic

Suring summer in Fay, the Sun is

farthest north of the celestial equator

Epicycles were invented to

explain retrograde motion

The major planets all show

prograde revolution

His model used epicycles


In Copernicus' model, retrograde motion was due to

motion of the observer

In Kepler's model,

the Sun is at one focus of the elliptical orbit

Kepler's 2nd law is known as

the "equal areas" law

An astronomical unit is

the distance of the Earth to the Sun

When we observe the stars near the Sun, we see them as they were

years ago

If we know the ___ of an object, we can calculate its distance from its apparent brightness.

energy output

Light waves longer than infrared are in the ___ part of the spectrum.


If you know the size and angular diameter of an object, you can calculate its


Black bodies radiate a(n) ___ spectrum.


Upward transitions in the atom's electron orbits produce

absorption lines

The bigger the blue shift is, the

faster the approach is

The largest telescopes are

reflecting telescopes

A spectrometer contains

a collimator

Full moon rises at


The faintest stars visible to naked eye are

magnitude of 6

In Ptolemy's model,

Earth was not on the epicycle

The line connecting the Sun to the planet is called

radius vector

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