The surprising discovery of a new class of pulsating X-ray stars

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.

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Really interesting.

“The notion that Cepheids could be X-ray active seemed far-fetched because these stars are only a few times more massive and a little hotter than the Sun,” said Engle. “Over a decade later, we’ve finally shown that they can in fact be X-ray variable”