A false color image composited of data from three sources. Credit: NASA/JPL-Caltech.
Cassiopeia A (Cas A) is a supernova remnant in the constellation Cassiopeia. In 1999, the Chandra X-Ray Observatory found a "hot point-like source" close to the center of the nebula that is quite likely a neutron star or black hole.
In the image on the right, red is infrared data from the Spitzer Space Telescope, orange is visible data from the Hubble Space Telescope, and blue and green are data from the Chandra X-ray Observatory. The cyan dot just off-center is the remnant of the star's core.
