Astronomy Final

Front 1

The most likely explanation of the high-speed motion of stars and gas near the Galactic center is that the stars and gas are orbiting a supermassive black hole.

Back 1

True.

Front 2

Most galaxies are receding from the Milky Way Galaxy.

Back 2

True

Front 3

Hubble's law can be used to determine distances to the farthest objects in the universe.

Back 3

True.

Front 4

Hubble's law states that

Back 4

the greater the distance to a galaxy, the greater is the galaxy's redshift.

Front 5

If the light from a galaxy fluctuates in brightness very rapidly, the region producing the radiation must be

Back 5

very small.

Front 6

Quasar spectra

Back 6

are strongly redshifted.

Front 7

T/F: Collisions between galaxies are rare and have little or no effect on the stars and interstellar gas in the galaxies involved.

Back 7

False

Front 8

T/F The quasar stage of a galaxy ends because the central black hole swallows up all the matter around it.

Back 8

True

Front 9

T/F Elliptical galaxies may be formed by mergers between spirals.

Back 9

True

Front 10

T/F On the largest scales, galaxies in the universe appear to be arranged on huge sheets surrounding nearly empty voids.

Back 10

True

Front 11

According to current theories of galactic evolution, quasars occur

Back 11

early in the evolutionary sequence

Front 12

The name "quasar" is derived from the description "quasi-stellar radio source." In this image the quasar (center) appears star-like. How are quasars very different from stars?

Back 12

Quasars may look like stars, but they are actually galaxies, no quasars are nearby, quasars are intrinsically much brighter than any star and much brighter than most galaxies. Quasars have highly redshifted spectral lines.

Front 13

Galaxy 1 is at a distance of 100 Mpc, and Galaxy 2 is at a distance of 350 Mpc. For which galaxy should we expect to see a higher recessional velocity?

Back 13

Galaxy 2

Front 14

When viewing a distant galaxy, the amount of look-back time in years is equal to which of the following?

Back 14

distance to the galaxy in light years

Front 15

Which feature of a galaxy seems to be related to the mass of the galaxy's central supermassive black hole?

Back 15

the size of the galaxy's central bulge

Front 16

How are the shapes of galaxies affected by collisions?

Back 16

They are twisted and distorted by tidal forces.

Front 17

Where are all the dead quasars?

Back 17

They lurk quietly at the hearts of normal-looking galaxies.

Front 18

Which galaxy is most likely to be active?

Back 18

a galaxy that has interacted with another galaxy relatively recently

Front 19

T/F The cosmological redshift is a direct measure of cosmic expansion.

Back 19

True

Front 20

The galactic distances used to measure the acceleration of the universe are determined by observations of

Back 20

exploding white dwarfs.

Front 21

The age of the universe is estimated to be

Back 21

greater than the age of the Milky Way Galaxy.

Front 22

T/F Deep surveys of the universe indicate that the largest structures in space are no larger than about 50 Mpc in size.

Back 22

False

Front 23

T/F The cosmological redshift is actually not a velocity at all, but a measure of the expansion of space-time.

Back 23

True

Front 24

The Tully-Fisher relation exists between the galaxy's luminosity and its

Back 24

rotation

Front 25

Active galaxies are very luminous because they

Back 25

contain supermassive black holes in their cores.

Front 26

T/F Herschel's attempt to map the Milky Way by counting stars led to an inaccurate estimate of the Galaxy's size because he was unaware of absorption by interstellar dust.

Back 26

True

Front 27

T/F Globular clusters trace out the large-scale structure of the Galactic disk.

Back 27

False

Front 28

T/F The Galactic halo contains only old stars.

Back 28

False

Front 29

T/F Stars and gas in the Galactic disk move in roughly circular orbits around the Galactic center.

Back 29

True

Front 30

In the Milky Way Galaxy, our Sun is located

Back 30

about halfway out from the center.

Front 31

The first stars that formed in the Milky Way now

Back 31

have random orbits in the halo.

Front 32

Most of the mass of the Milky Way exists in the form of

Back 32

dark matter

Front 33

What can we use to estimate the mass of the galavy?

Back 33

It's rotation curve

Front 34

T/F The Earth lies close to the center of the Galaxy.

Back 34

False

Front 35

T/F Population I stars came billions of years before Population II stars.

Back 35

False

Front 36

T/F The rotation curve for our Galaxy shows stars beyond the Sun moving slower than expected.

Back 36

False

Front 37

T/F The core of the Milky Way, Sagittarius A, is a strong radio source in the sky.

Back 37

True

Front 38

T/F Most elliptical galaxies contain only young stars.

Back 38

False

Front 39

T/F Irregular galaxies, although small, have lots of star formation taking place in them.

Back 39

True

Front 40

T/F Irregular galaxies, although small, have large H II regions and much on-going star formation for their size.

Back 40

True

Front 41

A galaxy containing substantial amounts of dark matter will

Back 41

Spin faster

Front 42

What main conclusion did Shapley draw from his measurements of the distances to the globular clusters?

Back 42

The sun is far from the center of the Milky Way.

Front 43

What was the topic of the Shapley-Curtis Debate of 1920?

Back 43

the location of the spiral nebulae

Front 44

Edwin Hubble resolved the Shapley-Curtis debate in 1924 by measuring the distance to large, bright spiral nebulae. What distance method did Hubble employ?

Back 44

the Cepheid variable star method

Front 45

How does an Sa galaxy differ from an Sc galaxy?

Back 45

The Sa galaxy has less gas and dust.

Front 46

What is the Milky Way in our sky?

Back 46

It is a bright band of light that goes around the entire sky and the disk of the galaxy of which we are a part.

Front 47

Would people living on a planet orbiting a star in an E0 type galaxy see a Milky Way?

Back 47

No, their galaxy has no disk.

Front 48

T/F Emission nebulae radiate mainly in the ultraviolet part of the electromagnetic spectrum

Back 48

False

Front 49

T/F Twenty-one-cm radiation can be used to probe the interiors of molecular clouds

Back 49

FALSE

Front 50

T/F The most massive stars form most rapidly

Back 50

TRUE

Front 51

T/F Brown dawrfs take a long time to form, but will eventually become visible as stars on the lower main sequence.

Back 51

FALSE

Front 52

T/F The formation of the first high-mass stars in a collapsing cloud tends to inhibit futher star formation within the cloud

Back 52

TRUE

Front 53

T/F Most stars form as members of groups or clusters

Back 53

TRUE

Front 54

T/F All of the single red-dwarf stars that ever formed are still on the main sequence today

Back 54

True

Front 55

T/F The sun will get brighter as it begins to run out of fuel in its core

Back 55

True

Front 56

T/F A planetary nebula is the disk of matter around a star that will eventually form a planetary system

Back 56

False

Front 57

T/F The various stages of stellar evolution predicted by thoery can be tested by observations of stars in clusters.

Back 57

True

Front 58

T/F A nova is a sudden outburst of light coming from an old main sequence star

Back 58

False

Front 59

T/F IT takes less and less time to fuse heavier and heavier elements inside a high mass star

Back 59

True

Front 60

T/F In a core-collapse supernova, the outer part of the corse rebounds from the inner, high-density core, destorying the entire outer part of the star

Back 60

True

Front 61

T/F Because of stellar nucleosyhthesis, the spectra of old stars show more heavy elements than those of young stars.

Back 61

False

Front 62

T/F Newly formed neutrons stars have extremely strong magnetic fields

Back 62

True

Front 63

T/F All millisecond pulsars are how, or once were, members of binary star systems

Back 63

True

Front 64

T/F The fact that gamma-ray burts are so distant means that they must be very energetic events

Back 64

True

Front 65

T/F All things, except light, are attracted by gravity

Back 65

False

Front 66

T/F According to general relitivity, space is warped, ot curved, by matter

Back 66

True

Front 67

T/F Although Visible light cannot escape froma black hole, high energy radiation, like gamma rays, can.

Back 67

False

Front 68

T/F THousands of black holes have been identified in our galaxy.

Back 68

False

Front 69

T/F Herschel's attempt to map out the Milky Way by counting thes stars led to an inaccurate estimate.

Back 69

True

Front 70

T/F Cepheid variables can be used to determine the distances to the nearest galaxies.

Back 70

True

Front 71

T/F Globular clusteres trace out the large-scale structure of the Galactic Disk

Back 71

False

Front 72

T/F The Galactic Halo contains about as much gas and dust as the Galactic Disk

Back 72

False

Front 73

T/F Stars and gas in the galactic disk move in roughly circular orbits around the Galactic Center

Back 73

True

Front 74

T/F The most likely explanation of the high speed motion of stars and gas near the galactic center is that they are orbiting a super massive black hole.

Back 74

True

Front 75

T/F Most galaxies are spirals like the milky way.

Back 75

False

Front 76

T/F Most eliptical galaxies contain only old stars.

Back 76

True

Front 77

T/F Irregular galaxies, although small, often have lost of star formation taking place inthem.

Back 77

True

Front 78

T/F Type I supernovae can be used to determine distances to galaxies

Back 78

True

Front 79

T/F Most galaxies are receding from the Milky Way Galaxy

Back 79

True

Front 80

T/F Hubbles Law can be used to determine distances to the farthest objects in the universe.

Back 80

True

Front 81

T/F Distant galaxies apppear to be much larger than those nearby

Back 81

False

Front 82

T/F Intergalactic gas in galaxy clusters emit large amounts of energy int he form of radio waves.

Back 82

False

Front 83

T/F Galaxy collisions are rare and have little or no effect on the stars and interstellar gas in the galaxies involved.

Back 83

False

Front 84

T/F The quasar stage of a galaxy ends because the central black hole swallows up all the matter around it.

Back 84

`True

Front 85

T/F Elliptical galaxies may be formed by mergers between spiral systems.

Back 85

Trie

Front 86

T/F The fact that a typical quasar would consume an entire galaxy's worth of mass in 10 billion years suggest that quasar lifetimes are relatively long.

Back 86

False

Front 87

T/F On the largest scales, galaxies in the universe appear to be arranged on huge sheets surrounding nearly empty voids.

Back 87

True

Front 88

T/F The image of a distant quasar can be split into several images by the gravitational field of a foreground cluster along the line of sight.

Back 88

True

Front 89

T/F Star A appears brighter than Star B, as seen from Earth. Therefore Star A must be closer to Earth than star B.

Back 89

False.

Front 90

T/F A star of apparent magnitude of +5 looks brighter than one of apparent magnitude of +2.

Back 90

False

Front 91

T/F Red giants are very bright because they are extremely hot.

Back 91

False

Front 92

T/F The radius of a star can be determined if the star's distance and luminosity are known.

Back 92

False

Front 93

T/F Astronomers can distinguish between main-sequence and giant stars by purely spectroscopic means.

Back 93

True

Front 94

T/F In a spectroscopic binary, the orbital motion of the component stars appears as variations in the overall apparent brightness of the system.

Back 94

False

Front 95

T/F It is possible to have a 1-billion year old O-Type main sequence star.

Back 95

False

Front 96

T/F Interstellar matter is quite evenly distributed throughout the Milky Way Galaxy.

Back 96

False

Front 97

How long does it take to travel a distance of one light-year?

Back 97

One year or Pi X 107 seconds

Front 98

What is the unit that we use to measure distances in the solar system?

Back 98

The AU or Astronomical Unit, which is equivalent to the distance between the Earth and the Sun.

Front 99

If the Earth rotated on it's axis twice as fast as it currently does but it's motion of the sun stayed the same then, among other things...

Back 99

the night would be half as long.

Front 100

A long thin cloud that stretched directly overhead would have an angular size of

Back 100

90 degrees

Front 101

In December we would see the sun in the directio of constellations...

Back 101

Sagittarius and Capricorn

Front 102

If the Moon's orbit around Earth were a little larger, solar eclipses would be...

Back 102

more likely to be annular

Front 103

What two pieces of information are needed to determine the diameter of a far away object?

Back 103

Distance and Angular Size

Front 104

T/F The solar day is longer than the sidereal day.

Back 104

True

Front 105

The most northern location on Earth where the sun can be seen directly overhead at noon is called

Back 105

The Tropic of Cancer

Front 106

What is the approximate position of Polaris on the Celestial Sphere?

Back 106

2" 30' x 89 Deg.

Front 107

When a think crescent of the moon is visible just before sunrise, the moonis in it's

Back 107

Waning Phase

Front 108

The Alpha star in a constellation is (when seen from Earth)

Back 108

The brightest star, when seen from Earth

Front 109

A major flaw in Copernicus' model was that it still had...

Back 109

circular orbits

Front 110

An asteroid with an orbit lying entirely inside Earth's orbit

Back 110

has an orbital semimajor axis of less than 1 AU

Front 111

Galileo's observations of Venus demonstrated that Venus must be

Back 111

Orbiting the sun.

Front 112

T/F The main advantage to using the Hubble Space Telescope is that focusing problems due to atmospheric disturbances are eliminated.

Back 112

True

Front 113

The habitable zone surrounding a main-sequence K-type star

Back 113

is larger than that of an M-type star.

Front 114

A radio wavelength emission observed by alies that comes from our solar system with a 24 hour periodic signal shape would come from

Back 114

human made signals on Earth

Front 115

The least well known factor in the Drake equation is

Back 115

the average lifetime of a technology cometent civilization.

Front 116

The chemical elements that form the basic molecules needed for life are found

Back 116

commonly throughout the cosmos.

Front 117

When the universe was 10 years old, the density of radiation was

Back 117

much greater than that of matter

Front 118

The horizon problem in the standard Big Bang model is solved by having the Universe

Back 118

inflate rapidly early in it's existence

Front 119

The galactic distances used to measure the acceleration of the universe are determined by obersvation sof

Back 119

exploding white dwarfs

Front 120

How do we resolve Oblers paradox

Back 120

finite age of the universe

Front 121

The Virgo Cluster, the Local Group and some other local galaxy clusters form the

Back 121

local super cluster

Front 122

A logical sequence of galaxy evolution would be

Back 122

quasar, active galaxy, normal galaxy

Front 123

More than ___ of the mass in the universe is dark.

Back 123

90%

Front 124

A Syfert galaxy

Back 124

looks like a normal galaxy but has an extremely bright galactic nuclei

Front 125

The Tully-Fisher method involves

Back 125

inferring the distance to a galaxy through a measurement of its rotation rate

Front 126

Charge particles spiraling around magnetic field lines produce

Back 126

sychroton radiation

Front 127

Active galaxies

Back 127

emit large amounts of energy at all wavelengths

Front 128

Active Galaxies are very luminous because they

Back 128

contain black holes in their core

Front 129

Quasar spectra are

Back 129

strongly redshifted

Front 130

If the light from a galaxy fluctuates in brightness very quickly, the region producing the radiation must be

Back 130

very small

Front 131

Hubble's Law Implies

Back 131

that the greater the distance to the galaxy the faster it is moving away from us.

Front 132

Within one MPC of the sun there are about

Back 132

45 galaxies

Front 133

Using the method of standard candles we could, in principle, estimate the distance to a campfire if we knew

Back 133

the number of logs burning

Front 134

Gravitational lensing leads to what?

Back 134

It causes light from distant stars to be bent or focused by unseen massive objects in it's path

Front 135

What do we expect to find at the center of our galaxy?

Back 135

A super massive black hole called SGR A

Front 136

A Cepheid variable star with luminosity 1000 times of the sun has a pulsation period of about

Back 136

4 days

Front 137

Most of the mass of the MIlky Way exists in the form of

Back 137

dark matter

Front 138

Stars in the outermost regions of the Milky Way

Back 138

orbit faster than astronomers would expect based on the galactic mass we can see

Front 139

A method for identifying black holes is to

Back 139

look for their effects on nearby companions

Front 140

WHat is Cygnus X-1?

Back 140

A candidate for an observable black hole binary system.

Front 141

The largest known black holes

Back 141

lie in the centers of the most massive galaxies

Front 142

A telescope searching for young bright stars would make the most discoveries if pointed

Back 142

within a spiral arm

Front 143

If light from a distant star passes close to a massive body, the light beam will

Back 143

bend towards the star due to gravity

Front 144

A spaceship nears an event horizon, a clock on the spaceship will be observed

Back 144

to run slowly

Front 145

What explanation does general relativity provide for gravity?

Back 145

Gravity is the result of curved spacetime

Front 146

The densely packed neutrons of a neutron star cannot balance the inward pull of gravity if the total mass is

Back 146

greater that Schwartzchild's limit of 3 solar masses

Front 147

In a hypernova, a very energetic supernova creates a

Back 147

black hole

Front 148

A proposed explanation for gamma ray bursters is

Back 148

hypernova making black holes and bi-polar gets coalesce of a neutron star binary

Front 149

Many of the milisecond pulsars lie in

Back 149

globular clusters

Front 150

Most pulsars are observed only _____ sources

Back 150

Radio

Front 151

The mass range for neuron stars is

Back 151

1.4 to 3 solar masses

Front 152

An object more massive than the sun but roughly the size of a city is a

Back 152

neutron star

Front 153

Important properties of young neutron stars are

Back 153

extremely rapid rotation and a strong magnetic

Front 154

In a neutron star, the core is

Back 154

made of compressed neutrons in contact with each other

Front 155

A 20 solar mass star will stay on the main sequence for 10 million years, yet its iron core can exist

Back 155

for only a day

Front 156

A 4 to 20 solar mass star leaves the main sequence on it's way to becoming a supergiant, it's luminosity

Back 156

remains roughly constant

Front 157

Which of the following best describes the evolutionary track of the most massive stars on a H-R Diagram>

Back 157

Horizontal Right

Front 158

The heaviest nuclei of all are formed

Back 158

in the core collapse which sets the stage for a type II supernova

Front 159

Type II supernovae occur when their cores start making

Back 159

iron

Front 160

The Changrasekhar Limit is

Back 160

the uppoer mass limit for a white dwarf

Front 161

Which of these does not depend on a close binary system to occur?

Back 161

A Type II supernova

Front 162

What can you conclude about a Type I supernova>

Back 162

It was originally a low mass star

Front 163

T/F if the universe had an edge, that would violate the assumption of isotropy in the cosmological principle.

Back 163

False.

Front 164

T/F The cosmic microwave background is the highly redshifted radiation of the early big bang.

Back 164

True

Front 165

T/F The theory of inflation predicts that the density of the universe is exactly equal to the critical density.

Back 165

True

Front 166

On the basis of our current best estimate of the present mass density of the universe, astronomers thing that

Back 166

the universe is infinite and will expand forever.

Front 167

The concept that on the grandest of scales, the universe is similar in appearance everywhere is

Back 167

homogeniety

Front 168

T/F The cosmological redshift is a direct measure of the expansion of the universe, thus independent of direction.

Back 168

True

Front 169

T/F The Big Bang was an expansion of matter into empty space

Back 169

False

Front 170

T/F Olber's Paradox is solved in part by the fact that the universe is not infinitely large nor infinitely old.

Back 170

True

Front 171

T/F The universe has been expanding at the same rate since it's formation.

Back 171

False

Front 172

T/F The fate or future of the universe depends only on the total number of galaxies and quasars.

Back 172

False

Front 173

T/F The cosmic microwave background is the total of all the radio emissions from all the galaxies and quasars in the universe.

Back 173

False

Front 174

T/F The horizon problem relates to the isotropy of the microwave background radiation.

Back 174

True