Astronomy Chapter Eleven

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

Upper right

Lower right

Upper left

Lower left

2. The spectral sequence in order of decreasing temperature is

OFBAGKM.

OBAGFKM.

OBAFGKM.

ABFGKMO.

BAGFKMO.

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

Surface temperature on the horizontal axis and luminosity on the vertical axis

Mass on the horizontal axis and luminosity on the vertical axis

Surface temperature on the horizontal axis and radius on the vertical axis

Mass on the horizontal axis and stellar age on the vertical axis

Interior temperature on the horizontal axis and mass on the vertical axis

4. What are the standard units for luminosity?

Watts

Joules

Newtons

Kilograms

Watts per second

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

Luminosity = apparent brightness / 4π x (distance)^2

Apparent brightness = luminosity / 4π x (distance)^2

Apparent brightness = luminosity x 4π x (distance)^2

Distance = luminosity / 4π x (apparent brightness)^2

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

Upper right

Lower right

Upper left

Lower left

7. A star's luminosity is the

Apparent brightness of the star in our sky.

Surface temperature of the star.

Lifetime of the star.

Total amount of light that the star will radiate over its entire lifetime.

Total amount of light that the star radiates each second.

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

Location where they are formed

Time they are formed

Luminosity they are formed with

Mass they are formed with

Color they are formed with

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

Upper right

Lower right

Upper left

Lower left

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

Upper right

Lower right

Upper left

Lower left

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

10 light-years.

10 parsecs.

0.1 light-year.

0.1 parsec.

Impossible to determine.

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

I

II

III

IV

V

13. The spectral sequence sorts stars according to

Mass.

Surface temperature.

Luminosity.

Core temperature.

Radius.

14. 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?

Visual binary

Eclipsing binary

Spectroscopic binary

Double star

None of the above

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

Upper right

Lower right

Upper left

Lower left

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

All stars in the cluster are approximately the same color.

All stars in the cluster are approximately the same age.

All stars in the cluster have approximately the same mass.

All stars in the cluster will evolve similarly.

There is an approximately equal number of all types of stars in the cluster.

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

Low-mass stars are cooler and less luminous than high-mass stars.

Low-mass stars are hotter and more luminous than high-mass stars.

Low-mass stars are cooler but more luminous than high-mass stars.

Low-mass stars are hotter but less luminous than high-mass stars.

Low-mass stars have the same temperature and luminosity as high-mass stars.

18. Cluster ages can be determined from

Main sequence fitting.

Main sequence turnoff.

Pulsating variable stars.

Spectroscopic binaries.

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

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

Is decreased by a factor of four, and the apparent brightness is decreased by a factor offour.

Is decreased by a factor of two, and the apparent brightness is decreased by a factor oftwo.

Remains the same, but the apparent brightness is decreased by a factor of two.

Remains the same, but the apparent brightness is decreased by a factor of four.

Is decreased by a factor of four, but the apparent brightness remains the same.