1. ITV Report

Amateur stargazer spots second supernova exploding star

The second "supernova'' exploding star discovered in less than two years by amateur astronomer Dave Grennan Photo: Dave Grennan/Raheny Observatory /PA Wire

An amateur astronomer has made Ireland's second discovery of a supernova in less than two years.

Dave Grennan was stargazing from his back garden in Raheny, north Dublin when he spotted the 123 million-year-old exploding star in the sky.

The 41-year-old said:

I knew exactly what it was. It wasn't a piece of dust on my camera, it was a supernova.

Mr Grennan also discovered the first supernova from Ireland using the same powerful telescope in September 2010.

He said his latest find, on Monday August 22, is a tribute to his hero, moonwalker Neil Armstrong who died on Saturday.

The first man to walk on the moon, Neil Armstrong Credit: NASA

Mr Grennan said he sat up until 4am examining his data and searching records to check if anyone else in the world has reported the star.

He then contacted the International Astronomical Union who formally designated the explosion as 2012ej.

Experts told him that the star was 100 times bigger than the sun and violently exploded in another galaxy, called IC2166, because it got too big and could not support its own weight.

"It is about 120 million light years away. That means it has taken 120 million years for the light from this explosion to travel the distance across the depths of the universe and reach us here on planet earth," Mr Grennan said.

"So we are looking back in time."

Dave Grennan and his wife Carol in their back garden observatory Credit: Julien Behal/PA Wire

David Moore, editor of Astronomy Ireland magazine, said a supernova is the biggest explosion in the universe, after the Big Bang.

He said:

It would be like billions of earths exploding all at once in an unimaginably violent event that would wipe out all life on our planet if it happened to any of the stars near our sun," To discover such an event, not to mention two, from Irish soil is a truly remarkable feat."

– David Moore, editor of Astronomy Ireland magazine