Aussie scientists help find huge planet

Sydney Morning Herald AAP, Friday 24 May 2005

Australian scientists are helping to bring the possibility of life on other planets a little closer to home.

University of Tasmania astronomers at the Canopus Observatory near Hobart are part of an international team that has discovered a huge new planet circling a star in the Milky Way galaxy.

One of the most distant ever discovered, it was found using a new scientific technique called gravitational microlensing, which increases the potential for locating Earth-size planets.

"It looks like a fairly extraordinary, massive planet," University of Tasmania Professor John Dickey told ABC radio.

"But we know many other planets around other stars, some of which are somewhat like this.

"What's special about this event is, it was discovered in a way, that is this gravitational lens method, which could, in principle, turn up Earth-like planets as well.

"Our other ways of finding planets around stars are only sensitive to very massive ones like Jupiter.

"We've been struggling with this technique to try to open the door to finding Earth-like planets, which I think is now much more hopeful."

Stefan Dieters, part of the Canopus Observatory team, also said the discovery of the planet had opened the doors to the solar system.

"Finding planets is the first step, finding Earth-size planets is the second step and then if you have an Earth-size planet where the temperature is in a nice range, then it's most likely you'll have life on it because life on Earth turns up in all sorts of places," he told AAP.

The Tasmanian scientists were part of an international effort which found the planet last month, but whose discovery has only just been announced.

Called OB-05-071, the planet is located about 15,000 light years from Earth, making it one of the most distant ever located.

The gravitational microlensing technique involves using the gravitational pull of a star to act as a giant lens, providing a better chance to make out a planet.

Dr Dieters said OB-05-071 - about 1,000 times the size of Earth - was only the second world to be discovered using microlensing.

He said scientists in Tasmania were notified of the event by two New Zealand amateur astronomers and researchers at Warsaw University in America.

The group monitored the event overnight on April 20, 21 and 26 to confirm the new planet's existence.

"Everybody in this game is a puzzle solver and we like finding something out and it's nice to be the first people on the planet to actually find something," Dr Dieters said.

"It's a piece of information, a piece of knowledge about ourselves and about our place in the universe."

Researchers are now racing to identify more planets before NASA introduces its own planet-finding technology.

"Several years down the track NASA's going to build a planet-finder satellite but we'll beat them," Dr Dieters said.

"Given a little bit of luck, we'll be right."

Gravitational microlensing occurs when a massive object in space crosses in front of a star shining in the background.

The object's gravitational pull bends the light rays from the more distant star and magnifies them like a lens.

On Earth, observers see the star get brighter as the lens crosses in front and then fade as the lens moves further away.

The presence of a planet orbiting the nearby star will modify the process in a predictable way.

The international microlensing team uses telescopes around the southern hemisphere in Hobart, Perth, South Africa and Chile.

The original article can be found here

[ In the News ]

[ Optical and X-ray Astronomy home page ]

[ Physics home page ]

URL: http://www.phys.utas.edu.au/physics/optastr/merc010705.htm
16th December 1998