Question

How can Cepheid variable stars helpful to figure out true brightness?

• A. These stars change their brightness over time
• B. These stars lower their brightness over time
• C. These stars raise their brightness over time
• D. None

Answer 1

The correct option is A These stars change their brightness over time

The brightness of the stars changes over time. The difference in the brightness over time allows calculating the distance to the star. This is the cepheid variable stars method that is used to measure the distance to stars beyond 100 light years.

These stars change their brightness over time