Just past midnight Indian time on 22 January, an astronomer at University College London and his students were taking a routine peek through their telescope when they noticed something odd: there was a new, bright ‘star’ at the edge of the Cigar Galaxy or M, some 11.4 million light years away. Before the London fog closed in and the view was lost, the group had taken photographs and contacted US astronomer friends. After a flurry of intercontinental activity, excited astronomers announced the discovery of a new supernova. The discovery has been announced in the scientific journal Nature.
A supernova is a star explosion. It throws out an enormous amount of energy, outshining a whole galaxy for a few days. It is estimated that mass is ejected from the exploding star at 30,000 kilometers per second. This one is of the type 1a, which happens when a white dwarf star which is old and dim, is loaded with excessive gas and dust causing a thermonuclear explosion. Two white dwarves colliding would also lead to a similar result.