cepheid
/ˈsɛfiɪd/
noun
- A type of star that regularly changes in brightness, used by astronomers to measure distances in space.
- By studying a cepheid, scientists can determine how far away its home galaxy is.
- The brightness of a cepheid pulses in a predictable pattern over several days.
- Astronomers used a cepheid to calculate the distance to the nearby galaxy.