Brightness Fluctuations of Stars in the Pleiades Cluster (image) Royal Astronomical Society Share Print E-Mail Caption The unique brightness fluctuations of each star reveal clues about their physical properties such as their size and rotation rate. Most of the bright stars in the Pleiades are a type of variable star called a slowly pulsating B star, but Maia is different, and shows evidence of a large chemical spot that crosses its surface as the star rotates with a 10-day period. Credit Credit: Aarhus University / T. White Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.