One of the most energetic explosive events known is a supernova. These occur at the end of a star's lifetime, when its nuclear fuel is exhausted and it is no longer supported by the release of nuclear energy. If the star is particularly massive, then its core will collapse and in so doing will release a huge amount of energy. This will cause a blast wave that ejects the star's envelope into interstellar space. The result of the collapse may be, in some cases, a rapidly rotating neutron star that can be observed many years later as a radio pulsar. While many supernovae have been seen in nearby galaxies, they are relatively rare events in our own galaxy. The last to be seen was Kepler's star in 2264 some 6,000 parsecs away. A supernova is likely to sterilize all systems within about 100 parsecs, so all unstable stars are monitored closely and on a regular basis by survey ships. There are no supernovae expected within human space within the next 1000 years.

Supernova Candidates

The only current supernova candidate in human space is IK Pegasi (HR 8210) (GRID 571021), located at a distance of 46 Parsecs from Sol. This closely orbiting binary star system consists of a main sequence star and a white dwarf 31 million kilometres apart. The dwarf has a mass 1.16 times that of Sol. It is believed that several hundred thousand years will probably need to pass before the white dwarf could accrete enough critical mass required to become a Type Ia supernova.