Question 1

Which of the following statements best explains why the apparent positions of constellations change throughout the year?

Accepted Answer

Earth's revolution around the Sun changes our nighttime view of the sky.

Question 2

If you observe the Big Dipper in the night sky, what can you infer about the distances between its stars?

Accepted Answer

The stars are at very different distances from Earth.

Question 3

A star emits light with a peak wavelength in the blue region of the spectrum. Compared to a red star, what can you conclude about its temperature?

Accepted Answer

It is hotter than the red star.

Question 4

If the apparent brightness $$B of a $$star is related to its luminosity $$L$$ and distance $$d by$$ $$B = \frac{L}{4\pi d^2$}$$, what happens to the apparent brightness if you move to a distance three times farther from the star?

Accepted Answer

It becomes one ninth as bright.

Question 5

On the Hertzsprung–Russell (H–R) diagram, where would you find a white dwarf star?

Accepted Answer

Lower left

Question 6

Which process is responsible for the energy produced in the Sun and other stars?

Accepted Answer

Thermonuclear reactions

Question 7

A star shrinks to one-tenth its original radius. By what factor does the gravitational force at its surface change, assuming its mass remains constant?

Accepted Answer

It becomes 100 times as much.

Question 8

If the Sun were to suddenly collapse into a black hole of the same mass, what would happen to Earth's orbit?

Accepted Answer

Earth's orbit would remain unchanged.

Question 9

Which of the following best describes a galaxy?

Accepted Answer

A huge assemblage of stars, interstellar gas, and dust.

Question 10

Which type of galaxy is the Milky Way classified as?

Accepted Answer

Spiral

Question 11

What is the main cause of the high rate of star formation in starburst galaxies?

Accepted Answer

Violent disturbances such as the collision of two galaxies.

Question 12

Which of the following is true about the motion of individual stars within a galaxy?

Accepted Answer

They move in elliptical orbits around the center of the galaxy.

Question 13

A dying star that has collapsed to a small size and is cooling off would appear in which part of the H–R diagram?

Accepted Answer

Lower left

Question 14

Which of the following best describes a black hole?

Accepted Answer

A region of space where gravity is so strong that not even light can escape.

Question 15

If a star's surface temperature is $$10,000\ \mathrm{K}$$ and its luminosity is $$100\ L_{\odot}$$, where would it likely be found on the H–R diagram?

Accepted Answer

On the main sequence, hotter and brighter than the Sun.

Question 16

Which of the following is NOT a type of galaxy?

Accepted Answer

Globular

Question 17

What is the final stage in the life cycle of a massive star?

Accepted Answer

It becomes a neutron star or black hole after a supernova.

Question 18

Which of the following best explains why the names of constellations are more interesting historically than scientifically?

Accepted Answer

They tell us about the cultures that named them.

Question 19

Which of the following is a correct statement about the structure of the universe?

Accepted Answer

Clusters of galaxies are larger than individual galaxies.

Question 20

If a star emits most of its light at a wavelength of $$700\ \mathrm{nm} ($$red), what can you infer about its temperature compared to a star emitting at $$400\ \mathrm{nm} ($$violet)?

Accepted Answer

The red star is cooler.

Stars and Galaxies: Structure, Properties, and Evolution

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