Which statement about the first quarter moon is FALSE?

Which statement about the first quarter moon is FALSE? A) It occurs about a week after the new moon B) It is the half moon of the evening sky C) From...

The last quarter phase of the Moon:

The last quarter phase of the Moon: A) Rises at sunset B) Sets at sunset C) Sets at sunrise D) Rises at sunrise E) Crosses the meridian at sunris...

While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?

While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it? A) 1 minute B) 3 hours C) 15 minutes D) 15...

You note that a particular star is directly overhead. It will be directly overhead again in:

You note that a particular star is directly overhead. It will be directly overhead again in: A) 1 hour B) 23 hours 56 minutes C) 24 hours D) 24 hours...

If your astrological sign is Aries, the Sun should be in the constellation Aries on your birthday. The dates, according to astrological tradition, during which the Sun is in the constellation Aries are March 21 to April 20th. In which constellation is the Sun actually in, during this time period?

If your astrological sign is Aries, the Sun should be in the constellation Aries on your birthday. The dates, according to astrological tradition, during...

Where would you be if the Sun sets for six continuous months, beginning on September 23rd?

Where would you be if the Sun sets for six continuous months, beginning on September 23rd? A) South Pole B) Antarctic Circle C) Arctic Circle D) North...

Where would you be if the Sun passes through your zenith on December 21st?

Where would you be if the Sun passes through your zenith on December 21st? A) Tropic of Cancer B) Antarctic Circle C) Equator D) Tropic of Capricorn E)...

When the Sun rises, it is located in the constellation Gemini. When the Sun sets later that same day, it will be:

When the Sun rises, it is located in the constellation Gemini. When the Sun sets later that same day, it will be: A) In the constellation Taurus B)...

Which statement about the length of a day is FALSE?

Which statement about the length of a day is FALSE? A) At the equator, every day is twelve hours long, then twelve hours of the night B) At the North...

If Taurus is now rising at sunset, which constellation will rise at sunset next month?

If Taurus is now rising at sunset, which constellation will rise at sunset next month? A) Gemini B) Aries C) Aquarius D) Scorpius E) Pisces Ans...

According to figure 1.15 in the textbook, in January the Sun is the constellation

According to figure 1.15 in the textbook, in January the Sun is the constellation A) Gemini B) Aquarius C) Leo D) Cancer Answer: ...

If Earth orbited the Sun in 9 months instead of 12, then, compared with a sidereal day, a solar day would be

If Earth orbited the Sun in 9 months instead of 12, then, compared with a sidereal day, a solar day would be  A) Longer B) Shorter C) Unchan...

Which physical property of Earth gives rise to the seasons?

Which physical property of Earth gives rise to the seasons? A) Changes in the day-night cycle B) The variation in its distance from the Sun C) The...

Night and day have approximately equal length at what time or times of the year?

Night and day have approximately equal length at what time or times of the year? A) Summer equinox B) Vernal and autumnal equinoxes C) Summer solstice D)...

Which of the following is NOT true about the astronomical feature is known as the "ecliptic"?

Which of the following is NOT true about the astronomical feature is known as the "ecliptic"? A) It is the plane in which Earth orbits the Sun B)...

From a location in the United States of America, a star is observed to be rising due East. Where will this star be located 6 hours later?

From a location in the United States of America, a star is observed to be rising due East. Where will this star be located 6 hours later? A) Setting...

Which solstice or equinox?

Which solstice or equinox? Answer: The Sun crosses the meridian 23.5 degrees lower in altitude than the celestial equator The noontime Sun casts...

Which solstice or equinox?

Which solstice or equinox? Answer: The Sun rises due east today, but will rise slightly north of due east tomorrow Spring equino...

The celestial sphere appears to move fastest about the ________.

The celestial sphere appears to move fastest about the ________. Answer: Equato...

About how many stars are visible on a clear, dark night with the naked eye alone?

About how many stars are visible on a clear, dark night with the naked eye alone? A) A few thousand B) Tens of thousands C) Millions and millions D)...

Into how many constellations in the celestial sphere divided?

Into how many constellations in the celestial sphere divided? A) 110 B) 12 C) 44 D) 88 E) 57 Answer: ...

What are constellations?

What are constellations? A) Groups of stars making an apparent pattern in the celestial sphere B) Ancient storyboards, useless to modern astronomers C)...

T/F From the South Pole, Polaris would appear directly overhead.

T/F From the South Pole, Polaris would appear directly overhead. Answer: Fals...

A long, thin cloud that stretched from directly overhead to the western horizon would have an angular size of

A long, thin cloud that stretched from directly overhead to the western horizon would have an angular size of  A) 45 B) 90 C) 180 D) 360 A...

The angular size of an object depends on which two quantities?

The angular size of an object depends on which two quantities? A) The object's actual size and its distance from us B) The object's distance from...

If Earth rotated twice as fast as it currently does, but its motion around the Sun stayed the same, then

If Earth rotated twice as fast as it currently does, but its motion around the Sun stayed the same, then A) The year would be half as long B) The...

In 1 second, light leaving Los Angels reaches approximately as far as

In 1 second, light leaving Los Angels reaches approximately as far as A)Venus, 4500000 km from Earth at closest approach B) The Moon, 384000 km C)...

The choices below each describe the appearance of an H-R diagram for a different star cluster. Which cluster is most likely to be located in the halo of our galaxy?

The choices below each describe the appearance of an H-R diagram for a different star cluster. Which cluster is most likely to be located in the halo...

The choices below each describe the appearance of an H-R diagram for a different star cluster. Which cluster is the youngest?

The choices below each describe the appearance of an H-R diagram for a different star cluster. Which cluster is the youngest?  A) The diagram...

How did astronomers discover the relationship between spectral type and mass for main-sequence stars?

How did astronomers discover the relationship between spectral type and mass for main-sequence stars?  A) by using computer models of hydrogen...

The approximate main-sequence lifetime of a star of spectral type O is

The approximate main-sequence lifetime of a star of spectral type O is A) 10,000 years. B) 3 million years. C) 300 million years. D) 10 billion y...

You observe a star and you want to plot it on an H-R diagram. You will need to measure all of the following, except the star's

You observe a star and you want to plot it on an H-R diagram. You will need to measure all of the following, except the star's  A) mass. B) distance. C)...

Careful measurements reveal that a star maintains a steady apparent brightness at most times, except that at precise intervals of 73 hours the star becomes dimmer for about 2 hours. The most likely explanation is that

Careful measurements reveal that a star maintains a steady apparent brightness at most times, except that at precise intervals of 73 hours the star...

To calculate the masses of stars in a binary system, we must measure their

To calculate the masses of stars in a binary system, we must measure their A) spectral types and distance from Earth. B) absolute magnitudes and luminosities. C)...

Sirius is a star with spectral type A star and Rigel is a star with spectral type B star. What can we conclude?

Sirius is a star with spectral type A star and Rigel is a star with spectral type B star. What can we conclude?  A) Rigel has a higher core temperature...

Which of the following statements about spectral types of stars is not generally true?

Which of the following statements about spectral types of stars is not generally true?  A) The spectral type of a star can be used to determine...

The star Vega has an absolute magnitude of about 4 and an apparent magnitude of about 0. Based on the definitions of absolute and apparent magnitude, we can conclude that

The star Vega has an absolute magnitude of about 4 and an apparent magnitude of about 0. Based on the definitions of absolute and apparent magnitude,...

A star with a parallax angle of 1/20 arcsecond is

A star with a parallax angle of 1/20 arcsecond is A) 20 light-years away. B) 1/20 parsec away. C) 20 parsecs away. D) 10 parsecs away. Answer:&...

Star A is identical to Star B, except that Star A is twice as far from us as Star B. Therefore

Star A is identical to Star B, except that Star A is twice as far from us as Star B. Therefore A) both stars have the same luminosity, but the apparent...

Based on the definition of apparent brightness, which units are appropriate for its measurement?

Based on the definition of apparent brightness, which units are appropriate for its measurement?  A) watts B) joules C) watts per square meter D)...

All stars are born with the same basic composition, yet stars can look quite different from one another. Which two factors primarily determine the characteristics of a star?

All stars are born with the same basic composition, yet stars can look quite different from one another. Which two factors primarily determine the characteristics...

What do we mean by the main-sequence turnoff point of a star cluster, and what does it tell us?

What do we mean by the main-sequence turnoff point of a star cluster, and what does it tell us?  A) It is the point in a star cluster beyond...

Which of the following statements comparing open and globular star clusters is not true?

Which of the following statements comparing open and globular star clusters is not true?  A) Open clusters are found only in the disk of the...

What is a white dwarf?

What is a white dwarf?  A) It is a main-sequence star of spectral type F, which tends to look white in colour. B) It is the remains of a star...

Suppose our Sun were suddenly replaced by a supergiant star. Which of the following would be true?

Suppose our Sun were suddenly replaced by a supergiant star. Which of the following would be true?  A) Earth would be inside the supergiant. B)...

What is the common trait of all main-sequence stars?

What is the common trait of all main-sequence stars?  A) They are in the final stage of their lives. B) They generate energy through hydrogen...

Each choice below lists a spectral type and luminosity class for a star. Which one is a red supergiant?

Each choice below lists a spectral type and luminosity class for a star. Which one is a red supergiant?  A) spectral type M1, luminosity class...

How is the lifetime of a star related to its mass?

How is the lifetime of a star related to its mass?  A) More massive stars live slightly shorter lives than less massive stars. B) More massive...

On an H-R diagram, stellar masses

On an H-R diagram, stellar masses A) can be determined for main-sequence stars but not for other types of stars. B) are greatest in the lower left...

On an H-R diagram, stellar masses

On an H-R diagram, stellar masses  A) can be determined for main-sequence stars but not for other types of stars. B) are greatest in the lower...

On an H-R diagram, stellar radii

On an H-R diagram, stellar radii  A) are greatest in the lower left and least in the upper right. B) decrease from left to right. C) are impossible...

The axes on a Hertzsprung-Russell (H-R) diagram represent

The axes on a Hertzsprung-Russell (H-R) diagram represent  A) mass and luminosity. B) luminosity and surface temperature. C) luminosity and apparent...

Which of the following terms is given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts?

Which of the following terms is given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts?  A)...

Astronomers can measure a star's mass in only certain cases. Which one of the following cases might allow astronomers to measure a star's mass?

Astronomers can measure a star's mass in only certain cases. Which one of the following cases might allow astronomers to measure a star's mass?  A)...

Our Sun is a star of spectral type

Our Sun is a star of spectral type A) F. B) M. C) G. D) S. Answer: ...

From hottest to coolest, the order of the spectral types of stars is

From hottest to coolest, the order of the spectral types of stars is A) OBAFGKM. B) OBAGFKM. C) ABFGKMO. D) OMKGFBA. E) ABCDEFG. Answer: ...

Star A has an apparent magnitude of 3 and Star B has an apparent magnitude of 5. Which star is brighter in our sky?

Star A has an apparent magnitude of 3 and Star B has an apparent magnitude of 5. Which star is brighter in our sky?  A) Star A B) Star B C) The...

Ten parsecs is about

Ten parsecs is about A) 150 million kilometres. B) 10,000 seconds. C) 10 parallax seconds of angle. D) 32.6 light-years. Answer: ...

If Star A is closer to us than Star B, then Star A's parallax angle is

If Star A is closer to us than Star B, then Star A's parallax angle is  A) smaller than that of Star B. B) larger than that of Star B. C) hotter...

Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?

Assuming that we can measure the apparent brightness of a star, what does the inverse square law for light allow us to do?  A) Determine both...

According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?

According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?  A) Its apparent...

The total amount of power (in watts, for example) that a star radiates into space is called its

The total amount of power (in watts, for example) that a star radiates into space is called its A) apparent brightness. B) absolute magnitude. C)...

What is the approximate chemical composition (by mass) with which all stars are born?

What is the approximate chemical composition (by mass) with which all stars are born?  A) three quarters hydrogen, one quarter helium, no more...

In order to understand star clusters, we need to be able to estimate their ages. What technique do scientists use for this?

In order to understand star clusters, we need to be able to estimate their ages. What technique do scientists use for this?  A) radioisotope...

Cluster ages can be determined from

Cluster ages can be determined from  A) main sequence fitting. B) main sequence turnoff. C) pulsating variable stars. D) spectroscopic binaries. E)...

Which of the following statements about a globular cluster is true?

Which of the following statements about a globular cluster is true?  A) All stars in the cluster are approximately at the same stage in evolution. B)...

Which of the following statements about an open cluster is true?

Which of the following statements about an open cluster is true?  A) All stars in the cluster are approximately the same colour. B) All stars...

Why are Cepheid variables so important for measuring distances in astronomy?

Why are Cepheid variables so important for measuring distances in astronomy?  A) They all have the same luminosity. B) They all have the same...

In a pulsating variable star, which characteristic of the star changes dramatically with time?

In a pulsating variable star, which characteristic of the star changes dramatically with time?  A) mass B) core temperature C) luminosity D)...

Which of the following luminosity classes refers to stars on the main sequence?

Which of the following luminosity classes refers to stars on the main sequence?  A) I B) II C) III D) IV E) V Answer: ...

Which of the following is true about low-mass stars compared to high-mass stars?

Which of the following is true about low-mass stars compared to high-mass stars?  A) Low-mass stars are cooler and less luminous than high-mass...

A star of spectral type G lives approximately how long on the main sequence?

A star of spectral type G lives approximately how long on the main sequence?  A) 1,000 years B) 10,000 years C) 1 million years D) 100 million...

A star of spectral type O lives approximately how long on the main sequence?

A star of spectral type O lives approximately how long on the main sequence?  A) 1,000 years B) 10,000 years C) 10 million years D) 100 million...

Which of the following characteristics of stars has the greatest range in values?

Which of the following characteristics of stars has the greatest range in values?  A) mass B) radius C) core temperature D) surface temperature E)...

Which of the following is the most common type of main-sequence star?

Which of the following is the most common type of main-sequence star?  A) an O star B) an A star C) an F star D) an M star E) a G star An...

The faintest star visible to the naked eye has an apparent visual magnitude of about

The faintest star visible to the naked eye has an apparent visual magnitude of about  A) 10. B) 6. C) 1. D) 0. E) -6. Answer: ...

On the main sequence, stars obtain their energy

On the main sequence, stars obtain their energy  A) from chemical reactions. B) from gravitational contraction. C) by converting hydrogen to...

You observe a star in the disk of the Milky Way, and you want to plot the star on an H-R diagram. You will need to determine all of the following, except the

You observe a star in the disk of the Milky Way, and you want to plot the star on an H-R diagram. You will need to determine all of the following, except...

On a Hertzsprung-Russell diagram, where would we find white dwarfs?

On a Hertzsprung-Russell diagram, where would we find white dwarfs?  A) upper right B) lower right C) upper left D) lower left Answer:&nbs...

On a Hertzsprung-Russell diagram, where would we find red giant stars?

On a Hertzsprung-Russell diagram, where would we find red giant stars?  A) upper right B) lower right C) upper left D) lower left Answer:&...

On a Hertzsprung-Russell diagram, where on the main sequence would we find stars that have the greatest mass?

On a Hertzsprung-Russell diagram, where on the main sequence would we find stars that have the greatest mass?  A) upper right B) lower right C)...

On a Hertzsprung-Russell diagram, where would we find stars that have the largest radii?

On a Hertzsprung-Russell diagram, where would we find stars that have the largest radii?  A) upper right B) lower right C) upper left D) lower...

On a Hertzsprung-Russell diagram, where would we find stars that are cool and luminous?

On a Hertzsprung-Russell diagram, where would we find stars that are cool and luminous?  A) upper right B) lower right C) upper left D) lower...

On a Hertzsprung-Russell diagram, where would we find stars that are cool and dim?

On a Hertzsprung-Russell diagram, where would we find stars that are cool and dim?  A) upper right B) lower right C) upper left D) lower lef...

Which of the following best describes the axes of a Hertzsprung-Russell (H-R) diagram?

Which of the following best describes the axes of a Hertzsprung-Russell (H-R) diagram?  A) surface temperature on the horizontal axis and luminosity...

Which of the following terms is given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts?

Which of the following terms is given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts?  A)...

Which of the following terms is given to a pair of stars that appear to change positions in the sky, indicating that they are orbiting one another?

Which of the following terms is given to a pair of stars that appear to change positions in the sky, indicating that they are orbiting one another?  A)...

Suppose you see two main-sequence stars of the same spectral type. Star 1 is dimmer in apparent brightness than Star 2 by a factor of 100. What can you conclude? (Neglect any effects that might be caused by interstellar dust and gas.)

Suppose you see two main-sequence stars of the same spectral type. Star 1 is dimmer in apparent brightness than Star 2 by a factor of 100. What can...

Which of the following persons used the ideas of quantum mechanics to describe why the spectral classification scheme is in order of decreasing temperature?

Which of the following persons used the ideas of quantum mechanics to describe why the spectral classification scheme is in order of decreasing temperature?  A)...

Which of the following persons reorganized the spectral classification scheme into the one we use today and personally classified over 400,000 stars?

Which of the following persons reorganized the spectral classification scheme into the one we use today and personally classified over 400,000 stars?  A)...

Which of the following statements about spectral types of stars is true?

Which of the following statements about spectral types of stars is true?  A) The spectral type of a star can be used to determine its surface...

Why is the spectral sequence of stars not alphabetical?

Why is the spectral sequence of stars not alphabetical?  A) The letters refer to the initials of the original discovery. B) The original alphabetical...

The spectral sequence in order of decreasing temperature is

The spectral sequence in order of decreasing temperature is  A) OFBAGKM. B) OBAGFKM. C) OBAFGKM. D) ABFGKMO. E) BAGFKMO. Answer: ...

The spectral sequence sorts stars according to

The spectral sequence sorts stars according to  A) mass. B) surface temperature. C) luminosity. D) core temperature. E) radius. Answer:&nb...

Which of the following statements about apparent and absolute magnitudes is true?

Which of the following statements about apparent and absolute magnitudes is true?  A) The magnitude system that we use now is based on a system...

The most distant stars we can measure stellar parallax for are approximately

The most distant stars we can measure stellar parallax for are approximately  A) 50 parsecs away. B) 500 parsecs away. C) 5,000 parsecs away. D)...

Suppose that you measure the parallax angle for a particular star to be 0.5 arcseconds. The distance to this star is

Suppose that you measure the parallax angle for a particular star to be 0.5 arcseconds. The distance to this star is  A) 0.5 light-year. B) 0.5...

Suppose you measure the parallax angle for a particular star to be 0.1 arcseconds. The distance to this star is

Suppose you measure the parallax angle for a particular star to be 0.1 arcseconds. The distance to this star is  A) 10 light-years. B) 10 parsecs. C)...

Why do astronomers often measure the visible-light apparent brightness instead of the total apparent brightness of a star?

Why do astronomers often measure the visible-light apparent brightness instead of the total apparent brightness of a star?  A) All stars put...

Which of the following correctly states the luminosity-distance formula?

Which of the following correctly states the luminosity-distance formula?  A) luminosity = B) apparent brightness = C) apparent brightness = luminosity...

If the distance between us and a star is doubled, with everything else remaining the same, the luminosity

If the distance between us and a star is doubled, with everything else remaining the same, the luminosity  A) is decreased by a factor of four,...

What are the standard units for apparent brightness?

What are the standard units for apparent brightness?  A) watts B) joules C) Newtons D) watts per second E) watts per square meter Answer:&...

A star's luminosity is the

A star's luminosity is the  A) apparent brightness of the star in our sky. B) surface temperature of the star. C) lifetime of the star. D) total...

What are the standard units for luminosity?

What are the standard units for luminosity?  A) watts B) joules C) Newtons D) kilograms E) watts per second Answer: ...

Since all stars begin their lives with the same basic composition, what characteristic most determines how they will differ?

Since all stars begin their lives with the same basic composition, what characteristic most determines how they will differ?  A) location where...

Approximately, what basic composition are all stars born with?

Approximately, what basic composition are all stars born with?  A) half hydrogen, half helium, no more than 2 percent heavier elements B) three-quarters...

In the formation of our Galaxy

In the formation of our Galaxy a) the spiral arms formed first. b) the globular clusters formed first. c) the disk component started out thin and...

The high-speed motion of gas and stars near the Milky Way Galaxy's centre is explained by

The high-speed motion of gas and stars near the Milky Way Galaxy's centre is explained by a) tidal forces from the Andromeda Galaxy. b) accretion...

The period-luminosity relationship is a crucial component of

The period-luminosity relationship is a crucial component of a) measuring distances with Cepheid variable stars. b) identifying the mass of the Galaxy's...

A nova involves

A nova involves a) mass transfer onto a white dwarf in a binary star system. b) repeated helium fusion flashes in red giants. c) rapid collapse of...

In a young star cluster, when more massive stars are evolving into red giants, the least massive stars are

In a young star cluster, when more massive stars are evolving into red giants, the least massive stars are a) ending their main-sequence stage. b)...

Very young stars in small clusters of 10-100 members are known as

Very young stars in small clusters of 10-100 members are known as a) OB associations. b) molecular cloud complexes. c) aggregates. d) globular clusters. e)...

The event that marks the end of a star's evolutionary life before becoming a white dwarf is

The event that marks the end of a star's evolutionary life before becoming a white dwarf is A) a nova. B) a planetary nebula. C) the exhaustion of...

The helium flash occurs

The helium flash occurs a) when T-Tauri bipolar jets shoot out. b) in the middle of the main sequence stage. c) in the red giant stage. d) during...

What is the single most important characteristic in determining the course of a star's evolution?

What is the single most important characteristic in determining the course of a star's evolution? a) density b) absolute brightness c) distance d)...

21-centimeter radiation is important because?

21-centimeter radiation is important because? a) its radio waves pass unaffected through clouds of interstellar dust. b) it arises from cool helium...

Stellar parallax is used to measure the

Stellar parallax is used to measure the a) sizes of stars. b) distances of stars. c) temperatures of stars. d) radial velocity of stars. e) brightness...

Wien's law tells us that the hotter an object, the _____ the peak wavelength of its emitted light.

Wien's law tells us that the hotter an object, the _____ the peak wavelength of its emitted light. a) longer b) more green c) heavier d) shorter e)...

When we observe stars near the centre of the Milky Way Galaxy, we detect light that was emitted from those stars about

When we observe stars near the centre of the Milky Way Galaxy, we detect light that was emitted from those stars about a) 200 million years ago b)...

What two observations allow us to estimate the Galaxy's mass?

What two observations allow us to estimate the Galaxy's mass? a) the Sun's mass and velocity in orbit around the galactic center b) the rotation of...

Compared to stars like the Sun in the disk of the Milky Way, stars that populate the extended spheroidal halo of the galaxy were born

Compared to stars like the Sun in the disk of the Milky Way, stars that populate the extended spheroidal halo of the galaxy were born a) earlier,...

The primary reason that massive O-type stars are not found in the galactic halo is that they are

The primary reason that massive O-type stars are not found in the galactic halo is that they are a) too massive to be kicked into the halo from the...

Kepler's Third Law does NOT apply to the motion of

Kepler's Third Law does NOT apply to the motion of a) a satellite orbiting Earth. b) a comet around the Sun. c) one star about another in a binary...

Which of these is not a typical part of our Galaxy's spiral arms?

Which of these is not a typical part of our Galaxy's spiral arms?  a) OB associations b) open clusters c) giant molecular clouds d) emission...

Our Sun is located in the Milky Way Galaxy

Our Sun is located in the Milky Way Galaxy a) about 30 Kpc from the center in the halo. b) 30,000 light-years from the center in a globular cluster. c)...

The location of the galactic centre was identified using

The location of the galactic centre was identified using a) supernova remnants. b) white dwarf stars in the spiral arms. c) giant variable stars in...

A nova involves

A nova involves a) mass transfer onto a white dwarf in a binary star system. b) repeated helium fusion flashes in red giants. c) rapid collapse of...

A white dwarf can explode when

A white dwarf can explode when a) its mass exceeds the Chandrasekhar limit. b) its electron degeneracy increases enormously. c) fusion reactions increase...

A key feature of globular clusters is that they have

A key feature of globular clusters is that they have a ) very few cool stars. b) the oldest stars in our Galaxy. c) lots of massive main sequence...

If two stars are on the main sequence, and one is more luminous that the other, we can be sure that the

If two stars are on the main sequence, and one is more luminous that the other, we can be sure that the a) more luminous star will have a longer lifetime. b)...

Astronomers determine the age of star clusters by observing

Astronomers determine the age of star clusters by observing a) the number of main sequence stars. b) the ratio of giants to supergiants. c) the luminosity...

All stars in a stellar cluster have roughly the same

All stars in a stellar cluster have roughly the same a) temperature. b) color. c) distance. d) mass. e) luminosity Answer: c) distance...

Stars like our Sun will end their lives as

Stars like our Sun will end their lives as a) red giants. b) pulsars. c) black holes. d) white dwarfs. e) red dwarfs. Answer: d) white dwa...

During formation, the Sun evolved toward the main sequence as shown in the figure. The Sun will evolve away from the main sequence when

During formation, the Sun evolved toward the main sequence as shown in the figure. The Sun will evolve away from the main sequence when a) its core...

A star like our Sun will spend most of its "shining" lifetime

A star like our Sun will spend most of its "shining" lifetime a) as a protostar. b) as a red giant. c) as a main-sequence star. d) as a white dwarf. e)...

What is a T-Tauri star?

What is a T-Tauri star?  a) a collapsing cloud of gas about to become a protostar b) a dying star c) a cool main sequence star d) a star releasing...

The reddish colour of emission nebulae indicates that

The reddish colour of emission nebulae indicates that a) gas and dust is moving away from Earth. b) hydrogen gas is present. c) dying stars have recently...

Some regions of the Milky Way's disk appear dark because

Some regions of the Milky Way's disk appear dark because a) there are no stars there. b) stars in that direction are obscured by interstellar gas. c)...

Objects more massive than our Sun form into stars

Objects more massive than our Sun form into stars a) much slower, over billions of years. b) in about the same time. c) much faster, over tens of...

If an interstellar cloud contract to become a star, it is due to which force?

If an interstellar cloud contract to become a star, it is due to which force? a) electromagnetic b) nuclear strong c) nuclear weak d) gravitational e)...

Stars are formed from cold interstellar gas clouds made up of

Stars are formed from cold interstellar gas clouds made up of a) atomic gas of mostly hydrogen, oxygen, carbon, and nitrogen. b) molecular hydrogen...

Astronomers use the term nebula to refer to

Astronomers use the term nebula to refer to a) outer envelopes of dying stars that drift gently into space. b) remnants of stars that die by supernova. c)...

Interstellar gas is composed primarily of

Interstellar gas is composed primarily of a) 90% hydrogen, 9% helium, and 1% heavier elements. b) molecules including water and CO2. c) 50% hydrogen,...

Which spectral classification and type corresponds to a star like the Sun?

Which spectral classification and type corresponds to a star like the Sun? a) B81A b) GIII c) M5V d) G2V e) K2V Answer: d) G2...

What are the two most important intrinsic properties for classifying stars?

What are the two most important intrinsic properties for classifying stars? a) distance and surface temperature b) luminosity and surface temperature c)...

Two stars have the same surface temperature, but the radius of one is 10 times that of the other. The larger star is

Two stars have the same surface temperature, but the radius of one is 10 times that of the other. The larger star is a) the same luminosity b) twice...

Which property of a star would not change if we could observe it from twice as far away?

Which property of a star would not change if we could observe it from twice as far away? a) angular size b) flux c) color d) parallax e) a,b, and...

Which of the following quantities do you need in order to calculate a star's luminosity?

Which of the following quantities do you need in order to calculate a star's luminosity? a) apparent brightness b) Doppler shift of spectral lines c)...

In the stellar magnitude system invented by Hipparchus, a smaller magnitude indicates a _____ star.

In the stellar magnitude system invented by Hipparchus, a smaller magnitude indicates a _____ star. a) brighter b) hotter c) cooler d) fainter e)...

Two identical stars, one 5 ly from Earth, and a second 50 ly from Earth are discovered. How much fainter does the farther star appear to be?

Two identical stars, one 5 ly from Earth, and a second 50 ly from Earth are discovered. How much fainter does the farther star appear to be? a) square...

For two stars of the same apparent brightness, the star closer to the Sun will generally have

For two stars of the same apparent brightness, the star closer to the Sun will generally have a) a higher flux b) a hotter temperature c) a lower...

If the parallax of a star is measured to be 0.1 seconds of arc, its distance is

If the parallax of a star is measured to be 0.1 seconds of arc, its distance is a) 10 astronomical units b) 33 ly c) 3.3 ly d) 0.1 parsec e) 1.0 parsec Answer: b)...

How big is a Parsec?

How big is a Parsec? Answer: 3.1x10^16...

If the parallax of a star is measured to be 0.1 seconds of arc, its distance is

If the parallax of a star is measured to be 0.1 seconds of arc, its distance is a) 10 astronomical units b) 10 parsecs c) 1 parsec d) 0.1 parsec e)...

How many radians in 60 degrees?

How many radians in 60 degrees? a) 3.14159 b) p/6 c) p/3 d) 2p/60 Answer: c) p/...