The surprising discovery of a new class of pulsating X-ray stars
(PHYSorg.com Space & Earth)

A surprising new class of X-ray pulsating variable stars has been discovered by a team of American and Canadian astronomers led by Villanova University`s Scott Engle and Edward Guinan. Part of the Villanova Secret Lives of Cepheids program, the new X-ray observations, obtained by NASA`s Chandra X-ray Observatory and published Thursday, March 23rd in the Astrophysical Journal, reveal that the bright prototype of Classical Cepheids, d Cephei, is a periodic pulsed X-ray source.