Question

How do astronomers measure distance to nearby stars?

Answer 1

Parallax.

Explanation:

Parallax is a technique that is used to figure out the distance to a star. It involves viewing the same object (a star in this case) from two different perspectives. This is a difficult procedure and is commonly done by viewing the object of interest when Earth is in opposite positions in its orbit around the Sun.

Once the parallax angle `p` has been determined, distance `d` is simply the inverse:

`d = 1/p`

For further details and information, see this.