variable star

noun

|Updated on: 17 May 2018

Definition of variable star

: a star whose brightness changes usually in more or less regular periods

Recent Examples of variable star from the Web

So far, astronomers have estimated those distances using data from 10 well-studied, long-period variable stars in the Milky Way.

— National Geographic, "How 1.7 Billion Stars Were Mapped With Dazzling 3-D Precision," 25 Apr. 2018
For the local universe, these mile markers are Cepheid variable stars, which periodically pulse and share the same intrinsic brightness.

— National Geographic, "How 1.7 Billion Stars Were Mapped With Dazzling 3-D Precision," 25 Apr. 2018
Haro discovered flare stars, variable stars which experience unpredictable surges in brightness.

— brett molina, USA TODAY, "Google Doodle pays tribute to Mexican astronomer Guillermo Haro," 21 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'variable star.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.