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Class:ASTR 1412 - Stars and Universe
Subject:Astronomy - ASTR
University:Texas A & M University-Commerce
Term:Spring 2012
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The more massive a galaxy is The faster it rotates
A galaxy containing substantial amounts of dark matter will spin faster
According to X-ray observations, the space between galaxies in a galactic cluster is very hot
Relative to luminous stellar matter, the fraction of dark matter in clusters is greater than the fraction in glaxies
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The hubble deep field shows a patch of sky that has the same angular size as the thickness of a piece of string
Galaxies evolve by Merging to form larger galaxies
According to current theories of galactic evolution, quasars occur early in the evolutionary sequence
Many nearby galaxies were more active in the past
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If gravitionional lenses showed amore massive lensing galaxy the quasar images would be farther apart
A white dwarf can dramatically increase in brightness only if it has another star nearby
A nova differs from a supernova in that the nova is much less luminous
Which of the following stars will become hot enough to form elements heavier than oxygen A star that is eight times more massive than the sun
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A supernova whose luminosity declines steadily in time is most likely associated with a star that is Comparable in mass to the sun
A massive star becomes a supernova when it forms iron in its core
An observable supernova should occur in our galaxy about once every century
Which one of the following does not provide evidence that supernovae have occured in our galaxy The existence of binary stars in our galaxy
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Nuclear fusion in the sun will create elements up to and including oxygen
Most of the carbon in our bodies originated in the core of a red giant star
The silver atoms fround in jewelry originated in A supernova
A neutron star is about the same size as a U.S city
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a neutron star's immense gravitational attraction is due primarily to its small radius and large mass
The most rapidly blinking pulsars are those that spin fastest
The xray emission from a neutron star in a binary system comes mainly from heated material in an accretion disk around the neutron star
Gamma Ray burst are observed to occur approximately uniformly over the entire sky
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Black holes result from stars having initial masses more than 25 times the mass of the sun
If the sun were magically to turn into a black hole of the same mass Earth's orbit would remain unchanged
a meterstick in a spaceship traveling at half the speed of light would appear to have a length of .87 meters
the best place to search for black holes is in a region of space that has strong xray emissions
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The best evidence for supermassive black holes in the centers of galaxies is rapid gas motion and intense energy emissions
Most of the bright stars in our galaxy are located in the galactic disk
A cepheid variable star with luminosity 1000 times that of the sun has a pulsation period of roughly 3 days
Globular clusters are found mainly in the galactic halo
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Shapley measured the distances to globular clusters by using a comparison of the absolute and apparent magnitudes of variable stars
In the milky way galaxy, our sun is located about halfway out from the center
a telescope searching for newly formed stars would make the most discoveries if it were pointed within a spiral arm
The first stars that formed in the milky way now have random orbits in the the halo
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Galaxy rotation curve tells us that far from the center, the galaxy rotates more rapidly than we would expect based on the light we see
Most of the mass of the milky way exists in the form of dark matter
A black hole probably exists at the galactic cener because stars near the center of the milky way are orbiting some unseen object
Young stars in a galactic disk are mostly found in the spiral arms
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Astronmers classify elliptical galaxies by how flattened they appear
Using the method of standard candles, we can, in principle find the distance to a campfire is we know the number of logs used
Within 30 mpc of the sun, there are about a few thousand galaxies
A galaxy 500 million parsecs away has a velocity of roughly 35,000 km/s away from us
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If the light from a galaxy fluctuates in brightness very rapidly, the region producing the radiation must be Very small
Quasar spectra are strongly redshifted
Active galaxies are very luminous because they contain black holes in their cores
If observations made from the middle of a large city are isotropic then there are tall buildings in every direction
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The cosmological principle would be invalidated if we found that the observed structure of the universe depends on the direction in which we look
When we use Hubble's law to estimate the age of the universe, the answer we get is the same for all galaxies
Olber's paradox is resolved by the finite age of the universe
The galactic distances used to meausre the acceleration of the universe are determined by observations of exploding white dwarfs
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The observed acceleration of the universe means that the maount of dark energy exceeds the total mass-energy of matter in the universe
On the basis of our current best estimate of the present mass of density of the universe, astronomers think that The universe is infinite in extent and will expand forever
The age of the universe is estimated to be greater than the age of the milky way galaxy
the cosmic background radiation is observed to come from all directions equally
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Immediately after its birth, the universe was dominated by photons
Present day Grand Univfied Theories unite all of the fundatmental forces except the gravitational force
About half a million years after the big bang, the universe had cooled to the point that protons and electrons could combine to form atoms
One of the problems with the standard big bang model is that the temperature is almost exactly the same everywhere
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According to our best estimates, the line that best describes the universe is accelerating
It is likely that the density of the universe is made up mostly of dark energy

The horizon problem in the standard big bang model is solved by having the universe inflate rapidly early in its existence
The structure we observe in the universe is the result of dark matter clumping long ago
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Elements more massive than lithium were not formed in the early universe because the temperature was too low
Matter and energy clumping in the early universe result in small but observable red shifts.
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 The more massive a galaxy isThe faster it rotates
 A galaxy containing substantial amounts of dark matter willspin faster
 According to X-ray observations, the space between galaxies in a galactic cluster isvery hot
 Relative to luminous stellar matter, the fraction of dark matter in clusters isgreater than the fraction in glaxies
 The hubble deep field shows a patch of sky that has the same angular size asthe thickness of a piece of string
 Galaxies evolve byMerging to form larger galaxies
 According to current theories of galactic evolution, quasars occurearly in the evolutionary sequence
 Many nearby galaxieswere more active in the past
 If gravitionional lenses showed amore massive lensing galaxy the quasar images would befarther apart
 A white dwarf can dramatically increase in brightness only if ithas another star nearby
 A nova differs from a supernova in that the novais much less luminous
 Which of the following stars will become hot enough to form elements heavier than oxygenA star that is eight times more massive than the sun
 A supernova whose luminosity declines steadily in time is most likely associated with a star that isComparable in mass to the sun
 A massive star becomes a supernova when itforms iron in its core
 An observable supernova should occur in our galaxy about once everycentury
 Which one of the following does not provide evidence that supernovae have occured in our galaxyThe existence of binary stars in our galaxy
 Nuclear fusion in the sun willcreate elements up to and including oxygen
 Most of the carbon in our bodies originated inthe core of a red giant star
 The silver atoms fround in jewelry originated inA supernova
 A neutron star is about the same size asa U.S city
 a neutron star's immense gravitational attraction is due primarily to its small radius andlarge mass
 The most rapidly blinking pulsars are those thatspin fastest
 The xray emission from a neutron star in a binary system comes mainly fromheated material in an accretion disk around the neutron star
 Gamma Ray burst are observed to occurapproximately uniformly over the entire sky
 Black holes result from stars having initial massesmore than 25 times the mass of the sun
 If the sun were magically to turn into a black hole of the same massEarth's orbit would remain unchanged
 a meterstick in a spaceship traveling at half the speed of light would appear to have a length of.87 meters
 the best place to search for black holes is in a region of space thathas strong xray emissions
 The best evidence for supermassive black holes in the centers of galaxies israpid gas motion and intense energy emissions
 Most of the bright stars in our galaxy are located in the galacticdisk
 A cepheid variable star with luminosity 1000 times that of the sun has a pulsation period of roughly3 days
 Globular clusters are found mainlyin the galactic halo
 Shapley measured the distances to globular clusters by usinga comparison of the absolute and apparent magnitudes of variable stars
 In the milky way galaxy, our sun is locatedabout halfway out from the center
 a telescope searching for newly formed stars would make the most discoveries if it were pointedwithin a spiral arm
 The first stars that formed in the milky way nowhave random orbits in the the halo
 Galaxy rotation curve tells us thatfar from the center, the galaxy rotates more rapidly than we would expect based on the light we see
 Most of the mass of the milky way exists in the form ofdark matter
 A black hole probably exists at the galactic cener becausestars near the center of the milky way are orbiting some unseen object
 Young stars in a galactic disk aremostly found in the spiral arms
 Astronmers classify elliptical galaxies byhow flattened they appear
 Using the method of standard candles, we can, in principle find the distance to a campfire is we knowthe number of logs used
 Within 30 mpc of the sun, there are abouta few thousand galaxies
 A galaxy 500 million parsecs away has a velocity of roughly35,000 km/s away from us
 If the light from a galaxy fluctuates in brightness very rapidly, the region producing the radiation must beVery small
 Quasar spectraare strongly redshifted
 Active galaxies are very luminous because theycontain black holes in their cores
 If observations made from the middle of a large city are isotropic thenthere are tall buildings in every direction
 The cosmological principle would be invalidated if we found thatthe observed structure of the universe depends on the direction in which we look
 When we use Hubble's law to estimate the age of the universe, the answer we getis the same for all galaxies
 Olber's paradox is resolved bythe finite age of the universe
 The galactic distances used to meausre the acceleration of the universe are determined by observations ofexploding white dwarfs
 The observed acceleration of the universe means thatthe maount of dark energy exceeds the total mass-energy of matter in the universe
 On the basis of our current best estimate of the present mass of density of the universe, astronomers think thatThe universe is infinite in extent and will expand forever
 The age of the universe is estimated to begreater than the age of the milky way galaxy
 the cosmic background radiation is observed to come fromall directions equally
 Immediately after its birth, the universe wasdominated by photons
 Present day Grand Univfied Theories unite all of the fundatmental forces exceptthe gravitational force
 About half a million years after the big bang, the universe had cooled to the point thatprotons and electrons could combine to form atoms
 One of the problems with the standard big bang model is thatthe temperature is almost exactly the same everywhere
 According to our best estimates, the line that best describes the universe isaccelerating
 It is likely that the density of the universe is made up mostly ofdark energy

 The horizon problem in the standard big bang model is solved by having the universeinflate rapidly early in its existence
 The structure we observe in the universe is the result ofdark matter clumping long ago
 Elements more massive than lithium were not formed in the early universe because the temperature wastoo low
 Matter and energy clumping in the early universe result insmall but observable red shifts.
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