Question 1

If a star with an absolute magnitude of − 5 has an apparent magnitude of +5, then its distance is

Accepted Answer

The distance modulus formula, which relates a star's absolute magnitude (M), apparent magnitude (m), and distance in parsecs (d), is given by $m - M = 5 \log_{10}(d) - 5$. Plugging in the given magnitudes (m = +5, M = -5), we get $5 - (-5) = 5 \log_{10}(d) - 5$, which simplifies to $10 = 5 \log_{10}(d) - 5$. Solving for $d$ gives us $d = 10^3 = 1000$ parsecs.

Question 2

The total mass of a binary system can be calculated from

Accepted Answer

The total mass of a binary system can be calculated using Kepler's Third Law, which relates the period and semimajor axis of the orbit to the total mass of the system. The other options do not directly provide a means to calculate the total mass.

Question 3

-Table 8-1 Use the chart below to answer the following question(s).
From the data given, which star in Table 8-1 is the closest to Earth?

Accepted Answer

The answer of 
-Table 8-1 Use the chart below to...

Question 4

-Table 8-1 Use the chart below to answer the following question(s).
From the data given, which star in Table 8-1 has the greatest surface temperature?

Accepted Answer

The answer of 
-Table 8-1 Use the chart below to...

Question 5

A spectroscopic binary shows periodic variations in its

Accepted Answer

A spectroscopic binary is a binary star system that cannot be resolved visually but shows periodic variations in its spectrum due to the Doppler effect. This means that the stars are moving toward and away from us, causing their spectral lines to shift back and forth. The periodic variations in the stars' radial velocity can be measured using spectroscopy, making A the best choice.

Question 6

Which of the following kinds of stars best obey the mass-luminosity relation?

Accepted Answer

The mass-luminosity relation applies to main-sequence stars, which are stars that are fusing hydrogen in their cores. The relation states that more massive main-sequence stars are also more luminous (brighter). This is because the fusion of more hydrogen atoms releases more energy, which causes the star to shine brighter.

Question 7

An eclipsing binary has been analyzed and it has been determined that the ratio of the mass of star A to the mass of star B is 6 and the total mass of the two stars is 26 solar masses. What are the masses of star A and star B?

Accepted Answer

Let's assume that the mass of star A is 6x and the mass of star B is x. Then we have:

6x + x = 26
7x = 26
x ≈ 3.7

Therefore, the mass of star A is approximately 6 times 3.7, or 22.3 solar masses, and the mass of star B is approximately 3.7 solar masses. Answer choice D matches this calculation.

Question 8

The diagram below shows the radial velocity curve of a double-line spectroscopic binary. Based on this radial velocity curve, which of the following statements is correct?

Accepted Answer

The answer of The diagram below shows the radial velocity...

Question 9

What is the total mass of a binary star system with P = 20 yr and a = 10 AU?

Accepted Answer

Using Kepler's Third Law, we can find the total mass of the binary star system:

P^2 = (4*pi^2/G(M1+M2))a^3

where P is the period, a is the semimajor axis, G is the gravitational constant, and M1 and M2 are the masses of the two stars.

Solving for M1 + M2, we get:

M1+M2 = (4*pi^2/G)a^3/P^2

Plugging in the given values, we get:

M1+M2 = (4*pi^2/6.67e-11 m^3/kg/s^2)*(10 AU)^3/(20 years)^2
M1+M2 = 2.5 solar masses

Therefore, the total mass of the binary star system is 2.5 solar masses, which corresponds to answer choice B.

Question 10

If a star has a parallax of 0.02 seconds of arc, then its distance is

Accepted Answer

The distance in parsecs (pc) can be calculated as the inverse of the parallax angle in arcseconds. Therefore, 1/0.02 = 50 pc.

Question 11

-Table 8-1 Use the chart below to answer the following question(s).
From the data given, which star in Table 8-1 has the greatest diameter?

Accepted Answer

The answer of 
-Table 8-1 Use the chart below to...

Question 12

The diagram below illustrates two stars in a visual binary system and the center of mass of this system. Based on this diagram, what is the ratio of the mass of star A to the mass of star B?

Accepted Answer

The answer of The diagram below illustrates two stars in...

Question 13

In the light curve below, what is the period of the eclipsing binary?

Accepted Answer

The period of the eclipsing binary can be determined by measuring the time between two consecutive minima or maxima. In this light curve, there are two consecutive minima that occur approximately 32.5 days apart, indicating a period of 32.5 days. Therefore, the correct choice is B.

Question 14

-Table 8-2 Use the chart below to answer the following question(s).
Which star in Table 8-2 is the closest to Earth?

Accepted Answer

The answer of 
-Table 8-2 Use the chart below to...

Question 15

-Table 8-1 Use the chart below to answer the following question(s)
From the data given, which star in Table 8-1 would appear the faintest in the night sky?

Accepted Answer

65 Tau has the lowest apparent magnitude, which means it appears the faintest in the night sky.

Question 16

Stars on the main sequence with the greatest mass

Accepted Answer

Stars with the greatest mass on the main sequence are known to be spectral type O stars. These stars have masses more than 20 times that of the Sun, making them the most massive stars on the main sequence.

Question 17

-Table 8-1 Use the chart below to answer the following question(s).
From the data given, which star in Table 8-1 has the greatest luminosity?

Accepted Answer

58 Ori has the greatest luminosity among the stars listed in Table 8-1.

Question 18

The star Algol is

Accepted Answer

Algol is known both as a spectroscopic binary, because its binary nature was determined through spectroscopy, and as an eclipsing binary, because its brightness variations are due to one star in the binary system passing in front of the other from our point of view, causing eclipses that affect its light curve.

Question 19

At what point in the light curve below is the cooler star in front of the hotter star of an eclipsing binary system?
​ 
​

Accepted Answer

The answer of At what point in the light curve...

Question 20

Which of the following kind of stars is most dense?

Accepted Answer

A white dwarf is the remnant core of a low to medium mass star that has exhausted all nuclear fuel in its core. It is incredibly dense, with a mass comparable to that of the Sun but a size similar to that of the Earth, resulting in a density of about 1 ton per cubic centimeter. Comparatively, other types of stars like supergiants or giants are less dense, while the Sun and main sequence stars fall between giant stars and white dwarfs in terms of density.

Quiz 8: The Family of Stars

If a star with an absolute magnitude of − 5 has an apparent magnitude of +5, then its distance is

The total mass of a binary system can be calculated from

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 is the closest to Earth?

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest surface temperature?

A spectroscopic binary shows periodic variations in its

Which of the following kinds of stars best obey the mass-luminosity relation?

An eclipsing binary has been analyzed and it has been determined that the ratio of the mass of star A to the mass of star B is 6 and the total mass of the two stars is 26 solar masses. What are the masses of star A and star B?

The diagram below shows the radial velocity curve of a double-line spectroscopic binary. Based on this radial velocity curve, which of the following statements is correct?

What is the total mass of a binary star system with P = 20 yr and a = 10 AU?

If a star has a parallax of 0.02 seconds of arc, then its distance is

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest diameter?

The diagram below illustrates two stars in a visual binary system and the center of mass of this system. Based on this diagram, what is the ratio of the mass of star A to the mass of star B?

In the light curve below, what is the period of the eclipsing binary?

-Table 8-2 Use the chart below to answer the following question(s) . Which star in Table 8-2 is the closest to Earth?

-Table 8-1 Use the chart below to answer the following question(s) From the data given, which star in Table 8-1 would appear the faintest in the night sky?

Stars on the main sequence with the greatest mass

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest luminosity?

The star Algol is

At what point in the light curve below is the cooler star in front of the hotter star of an eclipsing binary system?

Which of the following kind of stars is most dense?

Quiz 8: The Family of Stars

If a star with an absolute magnitude of − 5 has an apparent magnitude of +5, then its distance is

The total mass of a binary system can be calculated from

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 is the closest to Earth?

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest surface temperature?

A spectroscopic binary shows periodic variations in its

Which of the following kinds of stars best obey the mass-luminosity relation?

An eclipsing binary has been analyzed and it has been determined that the ratio of the mass of star A to the mass of star B is 6 and the total mass of the two stars is 26 solar masses. What are the masses of star A and star B?

The diagram below shows the radial velocity curve of a double-line spectroscopic binary. Based on this radial velocity curve, which of the following statements is correct?

What is the total mass of a binary star system with P = 20 yr and a = 10 AU?

If a star has a parallax of 0.02 seconds of arc, then its distance is

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest diameter?

The diagram below illustrates two stars in a visual binary system and the center of mass of this system. Based on this diagram, what is the ratio of the mass of star A to the mass of star B?

In the light curve below, what is the period of the eclipsing binary?

-Table 8-2 Use the chart below to answer the following question(s) . Which star in Table 8-2 is the closest to Earth?

-Table 8-1 Use the chart below to answer the following question(s) From the data given, which star in Table 8-1 would appear the faintest in the night sky?

Stars on the main sequence with the greatest mass

-Table 8-1 Use the chart below to answer the following question(s) . From the data given, which star in Table 8-1 has the greatest luminosity?

The star Algol is

At what point in the light curve below is the cooler star in front of the hotter star of an eclipsing binary system? ​ ​

Which of the following kind of stars is most dense?

At what point in the light curve below is the cooler star in front of the hotter star of an eclipsing binary system?