Submission + - A decade-long mystery has been solved
justelite writes: "A decade-long mystery has been solved using data from ESA's X-ray observatory XMM-Newton. The brightest member of the so-called 'magnificent seven' has been found to pulsate with a period of seven seconds.
The discovery casts some doubt on the recent interpretation that this object is a highly exotic celestial object known as a quark star."