Question 1

What information can we get from eclipsing binaries that we cannot get from visual binaries?

Accepted Answer

​ Because the orbital plane of...

Question 2

If a star is located at 10 pc, which of the following statements is correct?

Accepted Answer

A)   The star's apparent and absolute visual magnitudes are equal.
B)   The star's apparent and absolute visual magnitudes are 0.
C)   The star's apparent visual magnitude is --1.1 whereas the absolute visual magnitude is -5.
D)   Two of the other choices are correct.E) All of the above
F) B) and C)

Question 3

The most massive main-sequence stars are the M stars.

Accepted Answer

A) True 
 B)False

Question 4

On the H-R diagram below, indicate the location of the white dwarf stars.

Accepted Answer

An elongated region should be ...

Question 5

We can determine the surface temperature of a star from

Accepted Answer

A)   studying its continuous spectrum.
B)   studying its line absorption spectrum.
C)   measuring the star's luminosity.
D)   studying its continuous spectrum and measuring the star's luminosity.
E)   studying its continuous spectrum, studying its line absorption spectrum, and measuring the star's luminosity.F) A) and B)
G) B) and E)

Question 6

How do absolute visual magnitude and luminosity differ?

Accepted Answer

Absolute visual magnitude of a star is t...

Question 7

If a binary system has a period of 4 years and a separation of 5 AU, then the total mass is 7.8 solar masses.

Accepted Answer

A) True 
 B)False

Question 8

Absolute visual magnitude is

Accepted Answer

A)   the apparent magnitude of a star observed from Earth.
B)   the luminosity of a star observed from a distance of 1000 pc.
C)   the apparent magnitude of a star observed from a distance of 10 pc.
D)   the luminosity of a star observed from Earth.
E)   the apparent magnitude of a star observed from a distance of 10 pc and the luminosity of a star observed from Earth.F) B) and E)
G) A) and B)

Question 9

How does density divide the stars in the H-R diagram into three groups?

Accepted Answer

Density divides stars into thr...

Question 10

Diagram 8-1 Use the H-R diagram below to answer the following question(s) . 
Which star in Diagram 8-1 has the greatest surface temperature?

Accepted Answer

A)   Alnilam
B)   Antares
C)   Arcturus
D)   HR 5337
E)   Sirius BF) A) and C)
G) A) and B)

Question 11

If you hold out your thumb at arm's length and rapidly blink each eye closed in an alternating pattern, your thumb appears to move left and right. This exercise is an example of _____________.

Accepted Answer

The answer of If you hold out your thumb at...

Question 12

Why don't we see hydrogen Balmer lines in the spectra of stars with temperatures of 3,200 K?

Accepted Answer

A)   There is no hydrogen in stars this cool.
B)   The stars are hot enough that most of the hydrogen is ionized and the atoms cannot absorb energy.
C)   These stars are so cool that nearly all of the hydrogen atoms are in the ground state.
D)   Stars of this temperature are too cool to produce an absorption spectrum.
E)   Stars of this temperature are too hot to produce an absorption spectrum.F) B) and C)
G) None of the above

Question 13

The parallax angle of the Sun is 1 arc second.

Accepted Answer

A) True 
 B)False

Question 14

Stellar parallax is used to measure distances of celestial bodies within the solar system.

Accepted Answer

A) True 
 B)False

Question 15

Below is a radial velocity curve for a spectroscopic binary. Which of the stars is most massive? ____________________

Accepted Answer

The answer of Below is a radial velocity curve for...

Question 16

Proxima Centauri has an absolute visual magnitude of 15.5 and an apparent visual magnitude of 11.0. What is the distance to Proxima Centauri in units of pc?

Accepted Answer

A)   0.1
B)   100.1
C)   10-0.1
D)   None of the other choices are correct.E) All of the above
F) B) and C)

Question 17

The larger variation in brightness of a partially eclipsing system consisting of a B2 main-sequence star and an M2 main-sequence star occurs when the B2 star passes in front of the M2 star.

Accepted Answer

A) True 
 B)False

Question 18

For stars on the main sequence, the luminosity can be estimated by the formula L = ____________________.

Accepted Answer

The answer of For stars on the main sequence, the...

Question 19

The best sample of the true numbers of the different types of stars consists of

Accepted Answer

A)   stars that appear brightest in the sky to an observer on Earth.
B)   all of the stars within our solar system.
C)   all the stars within a given distance from Earth.D) None of the above
E) All of the above

Question 20

The spectra of the coolest stars contain strong absorption features (or lines)  of

Accepted Answer

A)   TiO molecules.
B)   ionized helium.
C)   helium.
D)   hydrogen.
E)   All of the other choices are correct.F) B) and C)
G) A) and E)

Exam 8: The Family of Stars

What information can we get from eclipsing binaries that we cannot get from visual binaries?

Correct Answerverified​ Because the orbital plane of...View AnswerShow Answer

On the H-R diagram below, indicate the location of the white dwarf stars.

Correct AnswerverifiedAn elongated region should be ...View AnswerShow Answer

If a binary system has a period of 4 years and a separation of 5 AU, then the total mass is 7.8 solar masses.

Correct AnswerverifiedShow Answer

Why don't we see hydrogen Balmer lines in the spectra of stars with temperatures of 3,200 K?

Correct AnswerverifiedShow Answer

The spectra of the coolest stars contain strong absorption features (or lines) of

Correct AnswerverifiedShow Answer

Absolute visual magnitude is

Correct AnswerverifiedShow Answer

Diagram 8-1 Use the H-R diagram below to answer the following question(s) . Which star in Diagram 8-1 has the greatest surface temperature?

Correct AnswerverifiedShow Answer

We can determine the surface temperature of a star from

Correct AnswerverifiedShow Answer

How do absolute visual magnitude and luminosity differ?

Correct AnswerverifiedAbsolute visual magnitude of a star is t...View AnswerShow Answer

The larger variation in brightness of a partially eclipsing system consisting of a B2 main-sequence star and an M2 main-sequence star occurs when the B2 star passes in front of the M2 star.

Correct AnswerverifiedShow Answer

Proxima Centauri has an absolute visual magnitude of 15.5 and an apparent visual magnitude of 11.0. What is the distance to Proxima Centauri in units of pc?

Correct AnswerverifiedShow Answer

Below is a radial velocity curve for a spectroscopic binary. Which of the stars is most massive? ____________________

Correct AnswerverifiedShow Answer

If you hold out your thumb at arm's length and rapidly blink each eye closed in an alternating pattern, your thumb appears to move left and right. This exercise is an example of _____________.

Correct AnswerverifiedShow Answer

The parallax angle of the Sun is 1 arc second.

Correct AnswerverifiedShow Answer

Stellar parallax is used to measure distances of celestial bodies within the solar system.

Correct AnswerverifiedShow Answer

The best sample of the true numbers of the different types of stars consists of

Correct AnswerverifiedShow Answer

If a star is located at 10 pc, which of the following statements is correct?

Correct AnswerverifiedShow Answer

How does density divide the stars in the H-R diagram into three groups?

Correct AnswerverifiedDensity divides stars into thr...View AnswerShow Answer

The most massive main-sequence stars are the M stars.

Correct AnswerverifiedShow Answer

For stars on the main sequence, the luminosity can be estimated by the formula L = ____________________.

Correct AnswerverifiedShow Answer

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Because the orbital plane of...
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An elongated region should be ...
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Absolute visual magnitude of a star is t...
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Density divides stars into thr...
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