G299 is the remnant of a Type Ia supernova explosion that happened thousands of years ago. Located somewhat close by, only about 16,000 light-years from Earth, this expanding debris field is more than 60 light-years across.
Credit: @nasachandraxray
X-ray (Chandra): NASA, CXC, U.Texas/S.Post et al.;
Infrared (2MASS): UMass, IPAC-Caltech, NASA, NSF