The closest Supernova candidate

[John Clark]

Actually the closest Supernova candidate is not Betelgeuse but IK Pegasi B, it's only 154 light years away versus 650 light years for Betelgeuse, that's still probably distant enough to be safe but its getting a little dicey.  IK Pegasi B is far too dim to be seen by the naked eye but it's in orbit around IK Pegasi A  which can be seen because it's about twice as massive as the sun and 8 times brighter.  IK Pegasi B is dim because it's a White Dwarf, a star about the size of the Earth but more massive than the sun.  IK Pegasi B is composed almost entirely of Carbon and Oxygen and is very hot and very dense, but it's not hot or dense enough to fuse the Carbon and Oxygen. However IK Pegasi B is already very close to the Chandrasekhar limit of 1.44 solar masses, and because it is in such a tight orbit around its much larger companion star (less than the orbit of Mercury)  IK Pegasi B is constantly gaining mass by gravitationally pulling matter off of IK Pegasi A.

When it reaches 1.44 solar masses it will no longer be able to support its own weight and will collapse in on itself, the resulting compression will increase the temperature and density until, almost instantly all the Carbon and Oxygen, virtually the entire star, will undergo thermonuclear fusion, And then everything will blow sky high in a Type 1a Supernova (someday Betelgeuse will be a Type 2 Supernova).

 John K Clark

[Lawrence Crowell]

It would be cool if it went soon. We would get a close up of our cosmological standard candle.

LC