An image of the Cepheid variable star RS Puppis. The most accurate observation to date of distant stars that periodically change in brightness may spark a rethink of the rate at which the universe ...

Cepheid variables are a type of star that undergo regular pulsations. The length of a Cepheid’s pulsations is always related to its intrinsic, or absolute, brightness in a simple way: The longer its ...

Taking advantage of the very high spatial resolution provided by the Very Large Telescope Interferometer, a team of French and Swiss astronomers [1] has measured directly the change in angular ...

Physicists have improved the accuracy of a technique that uses variable stars to measure distances in the universe, providing a new figure for its expansion rate. When you purchase through links on ...