Saturday, March 5, 2011

APOD: Cassiopeia A and a Cooling Neutron Star

Image Credit: X-ray: NASA / CXC / UNAM / Ioffe / D.Page, P.Shternin et al; Optical: NASA / STScI; Illustration: NASA/CXC/M.Weiss)

Supernova remnant Cassiopeia A (Cass A) is a comfortable 11,000 light-years away. Light from the Cass A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. The expanding debris cloud spans about 15 light-years in this composite X-ray/optical image, while the bright source near the center is a neutron star (inset illustration) the incredibly dense, collapsed remains of the stellar core. Still hot enough to emit X-rays, Cass A’s neutron star is cooling. In fact, 10 years of observations with the orbiting Chandra X-ray observatory find that the neutron star is cooling rapidly, so rapidly that researchers suspect a large part of the neutron star’s core is forming a frictionless neutron superfluid. The Chandra results represent the first observational evidence for this bizarre state of matter.

Source:NASA, Astronomy Picture of The Day

No comments:

Post a Comment