Caption: Circinus X-1, located in the plane of the Milky Way about 24,000 light years from Earth, is a fledgling supernova remnant and an oddity of the Milky Way. Known as an X-ray binary system, Circinus X-1 contains a neutron star, the dense cinder of the exploded star, a companion star and the glowing nebula of ionized gas that is the hallmark of a massive supernova explosion.
Image: X-ray: NASA/CXC/Univ. of Wisconsin-Madison/S. Heinz et al; Optical: DSS; Radio: CSIRO/ATNF/ATCA