A Backyard stargazer with a knack for discovery. - By Chris Pipos
It came to Bill Bradfield in a blur - and that was enough for him to discover another comet.
The 76-year-old father of three, who lives at Yankalilla on the Fleurieu Peninsula of South Australia, has stunned the scientific world with his uncanny knack which he puts down to "having a good eye".
What makes his latest find - the 18th comet he has discovered - so remarkable is that it was done with a simple $300 telescope .
" I was really excited after going for 9 years without a discovery." Mr. Bradfield said.
The former government rocket propulsion scientist has spent 900 hours gazing the heavens since finding his last comet in 1995.
No living amateur astronomer has discovered as many comets - with only 200 discovered by non-professionals .
Mr. Bradfield's discoveries started in 1972 and all carry his name, including the latest C/2004 F4 (Bradfield) , which he spotted from a roadside lookout 6km south of Yankalilla, on March 23, at 7.45pm. "I decided to look towards the west at low elevation just above the hills, I had only been sweeping backwards and forwards a couple of times before spotting it."
After sighting it, he sketched the nearby star field pattern and went home to match it with his astronomy charts to confirm the "dirty snowball" had not already been discovered.
The dirty snowball was in fact yet another comet - a ball of ice and snow.
Mr. Bradfield returned to the site the next night to confirm his discovery. "I was able to point the telescope in the right direction and bang, I saw it again, I was a bit surprised to see it because the weather was fairly bright. You couldn't see it with the naked eye."
The comet was 237 million km from Earth and estimated to be 10,000km in diameter. The find has earned mr. Bradfield up to $13,000 as part of the U.S.- administered Edgar Wilson Award, an incentive for amateur comet hunters, and recognition from the International
Astronomical Union, which names, numbers and registers new comets.
Despite the recognition, Mr. Bradfeild refuses to get carried away with his latest sighting.
"There are people that like to follow the development of comets regularly and note whether they're getting bigger or getting a tail," I'd prefer to spend my time looking for another one."
Mr. Bradfield spends about two hours a week stargazing at two spots near Yankalilla and also from his backyard, often using his handmade Newtonian reflector telescope. "It's all rough and ready," he said about his telescope, which was built in 1984 and includes the use of bricks to help counter-balance it. "You don't need chrome plating to discover a comet" he said.
For searching, he prefers country sites with less interference from light, and picks nights wiithout excessive moonlight or cloud - know as the 'astronomer's curse'.
Mr. Bradfield, who was awarded the Order of Australia in 1989 for his service to Astronomy, made his first discovery from a backyard in Deranacourt in 1972.