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astronomy final questions
How long is the lifetime of a star related to its mass?
the bigger the star the shorter it lives
what is a white dwarf?
exposed cores of stars that have died
do stars with high masses live longer than stars with low masses?
what cycle of star will our sun end its life in?
which of the milky way are false?
our solar system is very close to the center (Its not)
from the fact that virtually every galaxy is moving away from us and more distant galaxies are moving away from us at a faster rate than the closer ones, we conclude that..
the farther we look into space the further in the past we look.
reisen cake theory
more distant reisons move away faster
what is a black hole?
a bottomless pit on spacetime
what is the chemical composition of a solar nebula?
98% H and He gas
what 3 major changes occured in the solar nebula as it shrank in size?
heating, spinning, and flattening
what is the frost line?
the distance at which it was cold enough for ices for condense and form
what does accretion mean in terms of planet formation?
the process by which small seeds grew into planets called accretion
define white dwarf.
the hot compact corpse of a low mass star, typically with a mass similar to the sun
what is an accretion disk?
rapidly rotating disk of material that gradually falls inward as it orbits a star-like object
what does the nebular theory state?
how our solar system formed from a cloud of interstellar gas and dust
why do jovian planets have so many large moons?
accretion within the disks of gas surrounding individual jovian planets.
what is an asteroid?
a relativly small and rocky object that orbits a star
what is a comet?
a relatively small and icy object that orbits a star
what does cosmos mean?
the total sum of all matter and energy in terms of the universe
where did the material that earth is made out of come from?
what is the observable universe?
the portion of the entire universe that can be seen from earth
what scaled object would describe the size and distance of earth on the same scale? (sun=grapefruit)
earth is a ball point pen 15 meters away
what is the sun made out of?
H He has
cwhat is the smallest?
the size of a typical planet
which is the largest?
a typical galaxy
what is nuclear fusion?
the process by which lightweight atomic nuclei smash together and stick to make heavier nuclei
why does carl sagan say we are star stuff?
every material in the entire universe is made from stars
what is a lightyear?
the distance light can travel in one year
put addresses in order(solar system, milky way, you, earth, local supercluster, and local group
you, earth, solar system, milky way, local group, and local supercluster
where is our solar system located in our galaxy?
how many stars are in the milky way?
how big if an area will be covered by all 9 planet orbits of the solar system? (sun=grapefruit)
over 300 football fields
the universe is expanding..how?
the average distances between galaxies are increasing with time
the age of the universe is..
the farther we look into space the futher we look back into time
what color are the youngest galaxies?
how can you describe the milky way?
a spiral galaxy with a disk about 100,00 lightyears in diameter and containing between 100 billion stars and 1 trillion stars
what is equivilent to all the stars in the universe?
all the grains of sand on all of earths beaches
how long is human civilization? (cosmic calendar)
2 min. ago
how long ago did the dinosaurs become extinct? (cosmic calendar)
1 day ago
when did galileo discover that we live on a planet? (cosmic calendar)
1 sec ago
what is an astronomical unit?
the average distance between the earth and the sun. 150 million km
how old is the solar system?
4.5 billion years
what is the focal plane of a telescope?
the place where the image appears in focus
what is a reflaction telescope?
uses a precisly curved primary mirror to gather light
what a refracting telescope?
uses a transparent glass lense to collect and focus light
what would you use to determine the chemical compostion of a distant planet or star?
high spectral resolution
what is ligh pollution?
human made light that hinders astrnomical observations
the earths rotation is what?
24 hrs/1 day
the moons rotation is what?
18 moon days
an earths orbit is what?
if we have a new moon today, when will we have the next full moon?
why do we essentially see the same face of the moon when its appearent?
how did astronomy benefit ancient civilizations?
time keeping and keeping track of seasons
ptolemy was important because...?
he was the one who claim the earth to be the center ofthe universe
the ancient greeks get alot of attention for their contributions to science because...?
the geocentric model
why is the geocentric model the model of the universe?
it explains motions of the sun, moons, planets,and stars`
what is the big bang?
it states that all the matter in our observable universe all comes out in a single moment
the age of the universe is?
14-16 billion years old
what does our solar system consist of?
planets and stars and the sin and all objecs that orbit it
what is a typical galaxy?
milky way and a collection of a few 100 billion to 1 trillion stars all bound by gravity
whats the difference between a planet and a star?
fusion; planets are smaller, dimmer, and orbit the stars
who is tycho brahe?
he helped prove the sun centered model and he observed planetary motion
what spectral type is our sun?
a pair of stars that we can determine are orbiting each other only by measuring their periodic doppler shifts is called?
how are galaxies important to our existence?
the recycle heavy elements and produce stars
how are stellar masses arranged on an H-R diagram?
they are impossible to determine
were impacts extremely common in the young solar system but not today?
what does the nebular theory predict on how our solar system was formed?
through stars collisions with each other
did the moon form the same time as the earth?
if you lived on the moon, would you see full earth when we see our new moon?
which phase of the moon does a solar eclispe occur?
what is a nova?
a dramatic brightening of a star that lasts for a few weeks then sunsides
what is a neutron star?
the compact corpse of a high-mass star left over by a supernova
what is a pulsar?
a neutron star from which we see rapid pulses of radiation as it rotates
what do lightyears measure?
distance not speed
what is the ecliptic plane?
a plabe the refers to the earth orbit around the sun
how many stars are visible by the naked eye?
what is a constellation?
a region of the sky
what is the ecliptic?
the suns appearent annual path amoung the contellations
what is the celestial sphere?
the imaginary sphere on which objects in the sky appear to reside when observed for earth
what is the meridian?
a half curcle extending from your horizon due south, through your zenithto your horizon due north
what is a zenith?
the point directly over your head
stars are visible in the local sky on any clear night of the year, at any time of night, what are they called?
what are the axes on the H-R diagram?
x=surface temp. y=luminosity
on the H-R diagram, how are stellar radii arranged?
they increase diagonally from lower left to upper right