Are there any stars close to Earth with the potential to supernova?
1 Answer
There are no stars which have the potential to supernova near enough to Earth to cause damage.
Explanation:
If a star goes supernova within a few tens of light years from the Earth then the gamma rays from the supernova can damage the ozone layer and greatly increase radiation levels.
Several stars have been identified as supernova candidates but they are too far away to cause damage. The nearest is IK Pegasi which is 150 light years away.
Sirius A and B is a binary system where Sirius A is a main sequence star and Sirius B is a white dwarf. They are about 8.6 light years from Earth. When Sirius A becomes a red giant Sirius B can supernova if it can collect enough material from Sirius A to reach the Chandrasekhar limit of 1.4 solar masses which will cause it to collapse into a neutron star. Currently Sirius A and B are too far apart for this to happen.
So, the only ways that a supernova can occur close enough to cause damage are if a supernova candidate star system comes within range or if Sirius A and B move closer too each other when Sirius A is a red giant. None of these is likely to happen for millions of years.