Question 1

Star C is a red star.Star D is a blue star.Which has a larger radius?

Accepted Answer

A) Star C has a larger radius. 
B) Star D has a larger radius. 
C) Stars C and D have the same radius. 
D) We also need to know the luminosities of the stars to determine their radii. 
E) We cannot determine the radii because color is not related to the radius. 
A) Star C has a larger radius. 
B) Star D has a larger radius. 
C) Stars C and D have the same radius. 
D) We also need to know the luminosities of the stars to determine their radii. 
E) We cannot determine the radii because color is not related to the radius.

Question 2

Stars with a larger brightness must be closer to us than fainter stars.

Accepted Answer

A) True 
 B)False

Question 3

The picture below shows an H-R diagram,with five stars labeled A through E.Which of the main-sequence stars has the smallest mass?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 4

The faster-moving star in a binary is:

Accepted Answer

A) the less massive star 
B) the more massive star 
C) the smaller radius star 
D) the larger radius star 
E) the lower temperature star 
A) the less massive star 
B) the more massive star 
C) the smaller radius star 
D) the larger radius star 
E) the lower temperature star

Question 5

What type of spectrum do most stars produce?

Accepted Answer

A) an absorption spectrum on top of a blackbody spectrum 
B) an emission spectrum on top of a blackbody spectrum 
C) an absorption spectrum on top of an emission spectrum 
D) a pure emission spectrum 
E) a pure blackbody spectrum 
A) an absorption spectrum on top of a blackbody spectrum 
B) an emission spectrum on top of a blackbody spectrum 
C) an absorption spectrum on top of an emission spectrum 
D) a pure emission spectrum 
E) a pure blackbody spectrum

Question 6

If we measure a star's luminosity and temperature,what other property of the star can we calculate? Explain how.

Accepted Answer

If we measure the luminosity L

Question 7

The blackbody spectra of a star with a temperature of 6000 K and a star with a temperature of 4000 K are shown below.
 
An astronomer uses a telescope to observe each of these two stars in both the blue and red filters.The blue filter is centered at 450 nm,while the red filter is centered at 660 nm.For each of the two stars,state through which filter that star will be the brightest.Explain your answer.

Accepted Answer

Looking at the blackbody curves,the 6000

Question 8

Explain how we can use spectroscopic parallax to determine the distance to a star farther away than a few hundred light-years.

Accepted Answer

First,we can determine the temperature o

Question 9

You observe two stars in a visual binary system using a blue filter that is centered at a wavelength of 550 nm and a red filter that is centered at a wavelength of 650 nm.Star A has a temperature of 10,000 K,while star B has a temperature of 4000 K,and you know that both stars are the same size.Which star will be the brightest in each filter?

Accepted Answer

A) Star A is the brightest in the blue filter,and star B is the brightest in the red filter. 
B) Star B is the brightest in the blue filter,and star A is the brightest in the red filter. 
C) Star A is the brightest in both filters. 
D) Star B is the brightest in both filters. 
E) Both stars have the same brightness in each filter. 
A) Star A is the brightest in the blue filter,and star B is the brightest in the red filter. 
B) Star B is the brightest in the blue filter,and star A is the brightest in the red filter. 
C) Star A is the brightest in both filters. 
D) Star B is the brightest in both filters. 
E) Both stars have the same brightness in each filter.

Question 10

The stars that have the largest radii are classified as:

Accepted Answer

A) giants 
B) ultragiants 
C) supergiants 
D) megagiants 
E) supernovae 
A) giants 
B) ultragiants 
C) supergiants 
D) megagiants 
E) supernovae

Question 11

Two stars with similar temperatures but different sizes will have:

Accepted Answer

A) similar spectral types but different luminosities 
B) similar luminosities but different brightnesses 
C) similar brightnesses but different distances 
D) similar distances but different masses e similar masses but different spectral types 
A) similar spectral types but different luminosities 
B) similar luminosities but different brightnesses 
C) similar brightnesses but different distances 
D) similar distances but different masses e similar masses but different spectral types

Question 12

What type of star is most common in the solar neighborhood?

Accepted Answer

A) subgiants 
B) supergiant 
C) white dwarf 
D) giant 
E) main-sequence 
A) subgiants 
B) supergiant 
C) white dwarf 
D) giant 
E) main-sequence

Question 13

The brightest stars in the sky also tend to be:

Accepted Answer

A) the highest mass stars 
B) the hottest stars in the sky 
C) very near to us 
D) very luminous 
E) all of the above 
A) the highest mass stars 
B) the hottest stars in the sky 
C) very near to us 
D) very luminous 
E) all of the above

Question 14

If a star's measured parallax is 0.2 arcsec,what is its distance?

Accepted Answer

A) 2 pc 
B) 5 pc 
C) 20 pc 
D) 40 pc 
E) 50 pc 
A) 2 pc 
B) 5 pc 
C) 20 pc 
D) 40 pc 
E) 50 pc

Question 15

The spectral class of a star is related to its:

Accepted Answer

A) luminosity 
B) brightness 
C) radius 
D) mass 
E) temperature 
A) luminosity 
B) brightness 
C) radius 
D) mass 
E) temperature

Question 16

Main-sequence stars range in mass from approximately:

Accepted Answer

A) 0.5 to 10 M☉ 
B) 0.08 to 150 M☉ 
C) 1 to 100 M☉ 
D) 0.1 to 75 M☉ 
E) 5 to 50 M☉ 
A) 0.5 to 10 M☉ 
B) 0.08 to 150 M☉ 
C) 1 to 100 M☉ 
D) 0.1 to 75 M☉ 
E) 5 to 50 M☉

Question 17

Which stars are the most common?

Accepted Answer

A) Stars with a larger mass and a larger radius than the Sun's are the most common. 
B) Stars with a smaller mass and a smaller radius than the Sun's are the most common. 
C) Stars with a larger mass and a smaller radius than the Sun's are the most common. 
D) Stars with a smaller mass and a larger radius than the Sun's are the most common. 
E) All of the above are equally common. 
A) Stars with a larger mass and a larger radius than the Sun's are the most common. 
B) Stars with a smaller mass and a smaller radius than the Sun's are the most common. 
C) Stars with a larger mass and a smaller radius than the Sun's are the most common. 
D) Stars with a smaller mass and a larger radius than the Sun's are the most common. 
E) All of the above are equally common.

Question 18

When astronomers refer to "heavy elements," which elements are they talking about?

Accepted Answer

A) all elements 
B) all elements more massive than hydrogen 
C) all elements more massive than helium 
D) all elements more massive than carbon 
E) all elements more massive than iron 
A) all elements 
B) all elements more massive than hydrogen 
C) all elements more massive than helium 
D) all elements more massive than carbon 
E) all elements more massive than iron

Question 19

What are the two main chemical elements that make up the Sun? How much of the mass of the Sun is composed of elements other than these two?

Accepted Answer

By mass,the Sun is made up of

Question 20

What advantage do you gain by having two eyes that are separated on your face,rather than being very close together?

Accepted Answer

A) better collecting area,which allows you to see dimmer objects 
B) double vision,which allows you to see multiple objects at once 
C) color vision,which allows you to determine temperatures 
D) stereoscopic vision,which allows you to determine distances 
E) better magnification,which allows you to see smaller objects 
A) better collecting area,which allows you to see dimmer objects 
B) double vision,which allows you to see multiple objects at once 
C) color vision,which allows you to determine temperatures 
D) stereoscopic vision,which allows you to determine distances 
E) better magnification,which allows you to see smaller objects

Exam 13: Taking the Measure of Stars

Star C is a red star.Star D is a blue star.Which has a larger radius?

Stars with a larger brightness must be closer to us than fainter stars.

The picture below shows an H-R diagram,with five stars labeled A through E.Which of the main-sequence stars has the smallest mass?

The faster-moving star in a binary is:

What type of spectrum do most stars produce?

If we measure a star's luminosity and temperature,what other property of the star can we calculate? Explain how.

Explain how we can use spectroscopic parallax to determine the distance to a star farther away than a few hundred light-years.

The stars that have the largest radii are classified as:

Two stars with similar temperatures but different sizes will have:

What type of star is most common in the solar neighborhood?

The brightest stars in the sky also tend to be:

If a star's measured parallax is 0.2 arcsec,what is its distance?

The spectral class of a star is related to its:

Main-sequence stars range in mass from approximately:

Which stars are the most common?

When astronomers refer to "heavy elements," which elements are they talking about?

What are the two main chemical elements that make up the Sun? How much of the mass of the Sun is composed of elements other than these two?

What advantage do you gain by having two eyes that are separated on your face,rather than being very close together?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters