Irish Astronomer Spots Second Supernova

An amateur astronomer has discovered his second supernova in two years – from a shed in his back garden.

Dave Grennan says he had the shock of his life when he spotted the 123 million-year-old exploding star from his home in Raheny, north Dublin.

And he has dedicated his latest find to his hero, moonwalker Neil Armstrong who died on Saturday.

The 41-year-old said: "I was about to pack up and go to bed and the very last photo I took I downloaded and I nearly fell off my chair. I couldn't believe it.

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

"I had the shock of my life."

The software developer, who works for state transport company IE, discovered the first supernova from Ireland using the same powerful telescope in September 2010.

He said he sat up until 4am examining his data and searching records to check if anyone else in the world reported the star, before contacting the International Astronomical Union which formally designated the celestial 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."

Mr Grennan described his love of the night sky as a vocation, and the support of his wife Carol as unwavering.

Four years ago he discovered an asteroid, a minor planet just three metres-wide, and named it after his late mother Catherine Griffin who encouraged his interest in the stars when he was a boy.

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

"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," he explained.

"To discover such an event, not to mention two, from Irish soil is a truly remarkable feat."