Question

key ideas: the universe: stars
word bank: ☐ sun ☐ temperature ☐ size ☐ medium ☐ closer ☐ overheated ☐ farther ☐ compact
scientists use the ____ as a standard for measuring the size of other stellar (star) systems because it is the closest star to us and we know the most about it. the sun is a __-sized star, so it serves as a good reference point for comparing stars that are larger or smaller. by looking at how other stars’ temperatures and brightness compare to the sun, scientists can estimate the __ and ____ of other star systems.
hotter, brighter stars, like supergiants, are much larger and give off more energy, which means the planets in their system have to orbit ____ away to avoid being __ (burned). this creates a bigger system overall. cooler, dimmer stars, like red or white dwarfs, are much smaller, so their planets need to be __ to get enough heat and light. as a result, these systems are more ____ (smaller)
the universe: stars: practice

1. which of the following best describes the sun’s relationship to the overall scale of the h-r diagram?

a. the sun is one of the hottest stars.
b. the sun is larger and more luminous than most stars.
c. the sun is an average star compared to the majority
d. the sun is among the least luminous stars.
image of h-r diagram

1. which of the following correctly explains the relationship between a star’s temperature and luminosity on the h-r diagram?

a. stars with lower temperatures always have higher luminosities.
b. as temperature increases, the star’s luminosity generally increases, especially for main-sequence stars.
c. the star’s luminosity decreases as the temperature increases for all stars.
d. stars’ temperature and luminosity are unrelated on the h-r diagram.

1. which two of the following explain why blue stars appear on the left side of the h-r diagram?

a. they have a lower surface temperature than red stars.
b. they have a higher surface temperature than red stars.
c. they are hotter than the sun
d. they are cooler than the sun.
e. they are always less luminous than red stars

Explanation:

1. The Sun is a medium - sized star. In the H - R Diagram, it is an average star compared to the majority.
2. On the H - R Diagram, for main - sequence stars, as temperature increases, the star's luminosity generally increases.
3. Blue stars have a higher surface temperature than red stars and are hotter than the Sun, so they appear on the left side of the H - R Diagram.

Answer:

1. C. The Sun is an average star compared to the majority.
2. B. As temperature increases, the star’s luminosity generally increases, especially for main - sequence stars.
3. B. They have a higher surface temperature than red stars; C. They are hotter than the Sun.