How Can We Tell That Some Stars Are Relatively Close

question 33

Multiple Choice

How can we tell that some stars are relatively close to us in the sky?

• A)Some stars are occasionally eclipsed by the Moon, so they must be nearby.
• B)Some stars vary in brightness caused by sunspots that we can see because they are so close.
• C)Some stars appear to be extremely bright and must therefore be very close to us.
• D)Some stars appear to move periodically back and forth against the background stars because of the Earth's movement around the Sun.