Amateur Ireland Astronomer Discovers Unique Supernova in Remote Galaxy (Weekend Feature)

Fig1a An amateur stargazer officially became the first person in Ireland ever to discover a supernova. The explosion that caused the burst of light occurred an estimated 290 million years ago. The odds of making the discovery are almost as difficult to comprehend as the distance the celestial spectacle was far beyond the Milky Way -a thousand, million, million, million miles away in the UGC112 galaxy.

The discovery was confirmed officially by International astronomers earlier this week. Supernovae are stellar explosions that are can outshine entire galaxies for a short time, and they are the major source of heavy elements in the Universe. It’s estimated that a supernova will occur in each of the 900,000 known galaxies no more than once every 100 years.

Dave Grennan, a software developer by day, but at night he spends as much time as the Irish weather permits in his home-made observatory, which is a converted garden shed with a retractable roof  discovered the small blot in the early hours of September 17. Grennan said he had been stargazing since he was about five years old, and had always been fascinated by the stars. He bought his first telescope in 1991, and has continually upgraded his equipment. In 2005 he built his home observatory using standard DIY parts. The observatory is equipped with a 14 inch Cassegrain telescope.

Grennan's wife Carol analyzes the images he takes with his telescope and helps identify interesting objects. They discovered the supernova by comparing images of the galaxy UGC 112 taken in August and September. The signs were tiny, but David’s many years of experience helped him identify what they had discovered.

Grennan said the discovery was the result of a year’s work, during which he surveyed 2,611 galaxies. He said it was “mind-boggling” to be the first to see something that happened almost 300 million years ago, and the time-lag “is on a scale almost as difficult to comprehend as Ireland’s astronomical debt. 
I was just about to wrap up for the night as I was exhausted at about midnight when I said to myself: ‘come on Dave, how are you ever going to discover anything in bed?” he to a local Ireland newspaper. “So I programmed my telescope to photograph 100 different galaxies to see if there were any new stars to discover. I started looking through a few of the images until I came to the second and spotted a difference from the last time I photographed the galaxy.”

Over the last year Grennan has photographed 2,611 out of the 900,000 or so known galaxies with the high-tech telescope in his observatory. As part of another requirement, Dave sought an independent consultation from Professor Stephen Smartt of Queen’s University in Belfast who arranged for one of the most high tech telescopes in the world to be trained on the UGC112 galaxy to confirm the existence of the supernova.

But the first supernova spotted from Irish soil didn’t become official until Monday, October 4, when the International Astronomical Union at Harvard University concurred with Dave’s discovery and sent a telegram to all top and budding astronomers to announce the news.

The phenomenon has been given the official designation ‘supernova 2010 IK’ according to the time of year it was registered.

It’s thought that the star in UGC112 galaxy which Dave witnessed exploding was “stripped of its layers by another star” and could not support its own weight causing it to collapse and explode under the pressure. However, variances in this supernova suggest that this is the first supernova of its kind to be discovered so far.

David Moore, chairman of Astronomy Ireland, said the supernova would only be visible with the most powerful of telescopes over the next two to three months. “The supernova is a million, million times brighter than the sun but it’s practically invisible to the naked eye,” Mr Moore told Northside People. “It’s absolutely extraordinary that it wasn’t picked up by all the top astronomers with the biggest and most expensive telescopes around the world.This is the biggest thing ever discovered in Irish astronomy. I’ve been waiting for this to happen for decades.”

This is the second discovery for Grennan who discovered an asteroid – a minor planet just three metres wide, which he named Catherine Griffin after his late mother who encouraged his interest in stars when he was a boy.



"The Galaxy" in Your Inbox, Free, Daily