Question 1

At what distance are stars assumed to be from Earth when they are represented by their absolute (as opposed to their apparent)magnitude?

Accepted Answer

A)  10 ly 
B)  10 parsecs 
C)  10 AU 
D)  1 ly 
A)  10 ly 
B)  10 parsecs 
C)  10 AU 
D)  1 ly

Question 2

A particular star is at a distance of 20 pc from Earth.For this star,the apparent magnitude would be

Accepted Answer

A)  either larger or smaller than the absolute magnitude,depending on the temperature and diameter of the star. 
B)  a smaller number than the absolute magnitude. 
C)  a larger number than the absolute magnitude. 
D)  the same as the absolute magnitude because magnitude is independent of distance. 
A)  either larger or smaller than the absolute magnitude,depending on the temperature and diameter of the star. 
B)  a smaller number than the absolute magnitude. 
C)  a larger number than the absolute magnitude. 
D)  the same as the absolute magnitude because magnitude is independent of distance.

Question 3

Luminosity is measured in

Accepted Answer

A)  watts per square meter. 
B)  joules per second or watts. 
C)  parsecs. 
D)  arcseconds per year. 
A)  watts per square meter. 
B)  joules per second or watts. 
C)  parsecs. 
D)  arcseconds per year.

Question 4

Which of these stars would be the coolest?

Accepted Answer

A)  A red star 
B)  A yellow-white star 
C)  A blue star 
D)  This cannot be determined from the information given. 
A)  A red star 
B)  A yellow-white star 
C)  A blue star 
D)  This cannot be determined from the information given.

Question 5

Supergiant and giant stars make up about what percentage of the total population of stars?

Accepted Answer

A)  1% 
B)  10% 
C)  50% 
D)  99% 
A)  1% 
B)  10% 
C)  50% 
D)  99%

Question 6

Which of these stars would be the hottest?

Accepted Answer

A)  A red star 
B)  A yellow-white star 
C)  A blue star 
D)  This cannot be determined from the information given. 
A)  A red star 
B)  A yellow-white star 
C)  A blue star 
D)  This cannot be determined from the information given.

Question 7

The star Arcturus is classified as K2 III,which means that it is a

Accepted Answer

A)  hot giant. 
B)  cool giant. 
C)  cool main-sequence star. 
D)  cool supergiant. 
A)  hot giant. 
B)  cool giant. 
C)  cool main-sequence star. 
D)  cool supergiant.

Question 8

If two stars of different luminosity have the same temperature,a luminosity class II star will be smaller than a luminosity class V star.

Accepted Answer

A) True 
 B)False

Question 9

How bright a star appears in the sky for an Earth-based observer is called its apparent magnitude.

Accepted Answer

A) True 
 B)False

Question 10

The H-R diagram plots the pressure of a star versus its gravity.

Accepted Answer

A) True 
 B)False

Question 11

What are brown dwarfs and what are their characteristics?

Accepted Answer

Brown dwarfs are not really stars and no

Question 12

In order of decreasing temperature,the complete spectral sequence for stars and brown dwarfs,as determined by relative spectral absorption line strengths,is

Accepted Answer

A)  OFMGABKLT. 
B)  ABFGKLMOT. 
C)  OBAFGKMLT. 
D)  LMOFKGABT. 
A)  OFMGABKLT. 
B)  ABFGKLMOT. 
C)  OBAFGKMLT. 
D)  LMOFKGABT.

Question 13

A white dwarf is

Accepted Answer

A)  an object intermediate between planets and stars that will never become a star. 
B)  a star at the end of its life,with a size close to that of Earth. 
C)  any main-sequence star with a surface temperature between about 9000 K and 15,000 K. 
D)  a star at the beginning of its life,with a size 2-10 times that of the Sun. 
A)  an object intermediate between planets and stars that will never become a star. 
B)  a star at the end of its life,with a size close to that of Earth. 
C)  any main-sequence star with a surface temperature between about 9000 K and 15,000 K. 
D)  a star at the beginning of its life,with a size 2-10 times that of the Sun.

Question 14

Measurements indicate that a certain star has a very high intrinsic brightness (100,000 times as bright as our Sun),yet is relatively cool (3500 K).How can this be?

Accepted Answer

A)  There must be an error in observation because no star can have this form. 
B)  The star must be quite small. 
C)  The star must belong to the main sequence. 
D)  The star must be very large. 
A)  There must be an error in observation because no star can have this form. 
B)  The star must be quite small. 
C)  The star must belong to the main sequence. 
D)  The star must be very large.

Question 15

What is the relationship between stellar parallax (p)measured in seconds of arc and distance (d)measured in parsecs?

Accepted Answer

A)  d = 2p 
B)  d = p 
C)  1/d = 2p 
D)  p = 1/d 
A)  d = 2p 
B)  d = p 
C)  1/d = 2p 
D)  p = 1/d

Question 16

Sirius,in Canis Major (the large hunting dog of Orion),is the brightest star in the winter night sky.It has a parallax angle of 0.38 seconds of arc.Orion's other hunting dog,Canis Minor,has as its brightest star Procyon,with a parallax angle of 0.29 seconds of arc.Vega,in Lyra the Lyre (Harp),is the brightest star in the summer night sky.It has a parallax angle of 0.13 seconds of arc.Which of these stars is the nearest to Earth?

Accepted Answer

A)  Sirius 
B)  Procyon 
C)  Vega 
D)  It cannot be determined from this information alone. 
A)  Sirius 
B)  Procyon 
C)  Vega 
D)  It cannot be determined from this information alone.

Question 17

The greater the mass of a main sequence star,the greater its

Accepted Answer

A)  luminosity. 
B)  surface temperature. 
C)  radius. 
D)  All of these 
A)  luminosity. 
B)  surface temperature. 
C)  radius. 
D)  All of these

Question 18

What is the approximate ratio of the brightness of two stars whose apparent magnitudes differ by 1 magnitude?

Accepted Answer

A)  2.5 
B)  10 
C)  100 
D)  2 
A)  2.5 
B)  10 
C)  100 
D)  2

Question 19

The spectral class of the Sun is G2 and the star Enif is K2.From this information,we know that Enif is

Accepted Answer

A)  farther away from the Sun. 
B)  cooler than the Sun. 
C)  intrinsically brighter than the Sun. 
D)  hotter than the Sun. 
A)  farther away from the Sun. 
B)  cooler than the Sun. 
C)  intrinsically brighter than the Sun. 
D)  hotter than the Sun.

Question 20

Why do very cool stars have prominent absorption lines such as those from titanium oxide (TiO)?

Accepted Answer

Below 4000 K,certain atoms in a star's a

At what distance are stars assumed to be from Earth when they are represented by their absolute (as opposed to their apparent)magnitude?

A particular star is at a distance of 20 pc from Earth.For this star,the apparent magnitude would be

Luminosity is measured in

Which of these stars would be the coolest?

Supergiant and giant stars make up about what percentage of the total population of stars?

Which of these stars would be the hottest?

The star Arcturus is classified as K2 III,which means that it is a

If two stars of different luminosity have the same temperature,a luminosity class II star will be smaller than a luminosity class V star.

How bright a star appears in the sky for an Earth-based observer is called its apparent magnitude.

The H-R diagram plots the pressure of a star versus its gravity.

What are brown dwarfs and what are their characteristics?

In order of decreasing temperature,the complete spectral sequence for stars and brown dwarfs,as determined by relative spectral absorption line strengths,is

A white dwarf is

Measurements indicate that a certain star has a very high intrinsic brightness (100,000 times as bright as our Sun),yet is relatively cool (3500 K).How can this be?

What is the relationship between stellar parallax (p)measured in seconds of arc and distance (d)measured in parsecs?

The greater the mass of a main sequence star,the greater its

What is the approximate ratio of the brightness of two stars whose apparent magnitudes differ by 1 magnitude?

The spectral class of the Sun is G2 and the star Enif is K2.From this information,we know that Enif is

Why do very cool stars have prominent absorption lines such as those from titanium oxide (TiO)?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Inferring Patterns in Star Life Cycles

Predicting the Violent End of the Largest Stars

Exploring Our Galaxy

Investigating Other Galaxies

Observing the Evolution of the Universe

Filters

Exam 10: Observing Properties of Distant Stars

At what distance are stars assumed to be from Earth when they are represented by their absolute (as opposed to their apparent)magnitude?

A particular star is at a distance of 20 pc from Earth.For this star,the apparent magnitude would be

Luminosity is measured in

Which of these stars would be the coolest?

Supergiant and giant stars make up about what percentage of the total population of stars?

Which of these stars would be the hottest?

The star Arcturus is classified as K2 III,which means that it is a

If two stars of different luminosity have the same temperature,a luminosity class II star will be smaller than a luminosity class V star.

How bright a star appears in the sky for an Earth-based observer is called its apparent magnitude.

The H-R diagram plots the pressure of a star versus its gravity.

What are brown dwarfs and what are their characteristics?

In order of decreasing temperature,the complete spectral sequence for stars and brown dwarfs,as determined by relative spectral absorption line strengths,is

A white dwarf is

Measurements indicate that a certain star has a very high intrinsic brightness (100,000 times as bright as our Sun),yet is relatively cool (3500 K).How can this be?

What is the relationship between stellar parallax (p)measured in seconds of arc and distance (d)measured in parsecs?

The greater the mass of a main sequence star,the greater its

What is the approximate ratio of the brightness of two stars whose apparent magnitudes differ by 1 magnitude?

The spectral class of the Sun is G2 and the star Enif is K2.From this information,we know that Enif is

Why do very cool stars have prominent absorption lines such as those from titanium oxide (TiO)?

Predicting the Motions of the Stars, Sun, and Moon

Decoding the Hidden Messages in Starlight

Analyzing Scales and Motions of the Universe

Exploring Our Evolving Solar System

Uncovering Earths Systems

Exploring Terrestrial Surface Processes and Atmospheres

Observing the Dynamic Giant Planets

Looking for Life Beyond Earth

Probing the Dynamic Sun

Inferring Patterns in Star Life Cycles

Predicting the Violent End of the Largest Stars

Exploring Our Galaxy

Investigating Other Galaxies

Observing the Evolution of the Universe

Filters