AN AMATEUR astronomer has become the first person in Ireland to discover a supernova.
The stellar explosion, given the unromantic designation 2010ik, took place about 290 million years ago in a far-away galaxy and it has taken the light that long to travel across space to reach Earth.
Dave Grennan made the discovery in the galaxy UGC 112 while looking through photographs he took of the sky from his back garden observatory in Raheny.
He compared photographs taken of the area of sky in August and again in September and noticed a tiny black dot where none had been before.
The dot might be small but the explosion is unimaginably large. For the next 300 days or so, an infinitesimally small time in astronomical terms, it will outshine the combined light of all the billions of stars in that galaxy.
2010ik is thought to be a type 1b supernova. They happen when a huge star, much bigger than our sun, starts losing material to a smaller companion star. Eventually the larger star becomes so unstable it blows up in a catastrophic explosion.
Astronomers believe we are all products of an ancient supernova as only such an event could create the heavier elements that make up our planet. Supernovas are extremely rare; there has not been an observable one in our galaxy for 500 years and finding them means being able to memorise star fields and note tiny changes that signal a supernova.
Mr Grennan said the discovery was the result of a year’s work, having surveyed 2,611 galaxies before finding a supernova. It was “mind-boggling” to be the first person to witness an event that happened when dinosaurs roamed the Earth. “We are watching an event as it is unfolding, yet that event happened nearly 300 million years ago.” In the last couple of years, Mr Grennan has also discovered two asteroids. He named one, called 215016 Catherinegriffin, after his late mother.
