Using data from four telescopes, NASA were able to create an image of the remains of RCW86 in October 2011. Image Credit: X-ray: NASA/CXC/SAO & ESA; Infared: NASA/JPL-Caltech/B. Williams (NCSU)
All that remains after 1826 years.
RCW 86 is the oldest recorded example of a supernova, located approximately 8,000 light years away in the southern constellation of Circinus. It was described as a “guest star” by Chinese astronomers in 185 and remained in the sky for eight months.
Astronomers have determined that the explosion was caused by a Type 1a supernova, where a white dwarf was pushed beyond the brink of stability when a companion star “dumped” material onto it. The white dwarf blew away wind prior to exploding, clearing a cavity of very low density around the system.
The explosion was then able to expand much faster than would have been possible otherwise. This is the first time this type of cavity has been seen around a white dwarf before an explosion.
