Continue reading

13-01-09 XMM-Newton measures speedy spin of rare celestial object

XMM-Newton has caught the fading glow of a tiny celestial object,revealing its rotation rate for the first time.The new information confirms this particular object as one of an extremely rare class of stellar zombie – each one the dead heart of a star that refuses to die.There are just five so-called Soft Gamma-ray Repeaters (SGRs) known,four in the Milky Way and one in our satellite galaxy,the Large Magellanic Cloud.Each is between 10 and 30 km across,yet contains about twice the mass of the Sun.Each one is the collapsed core of a large star that has exploded,collectively called neutron stars.What sets the Soft Gamma-ray Repeaters apart from other neutron stars is that they possess magnetic fields that are up to 1000 times stronger.This has led astronomers to call them magnetars.SGR 1627-41 was discovered in 1998 by NASA’s Compton Gamma Ray Observatory when it burst into life emitting around a hundred short flares during a six-week period.It then faded before X-ray telescopes could measure its rotation rate.Thus,SGR 1627-41 was the only magnetar with an unknown period