|Australians part of international team that discovers four new planets|
* From: AAP
* December 15, 2009 7:25AM
AUSTRALIAN scientists are part of a team that has discovered four new planets, orbiting two stars similar to our sun.
An international team of astronomers using telescopes in Australia and Hawaii have discovered the planets.
The planets were found by Australian, American and British astronomers using the Anglo-Australian Telescope in NSW and the Keck Telescope in Hawaii.
Professor Chris Tinney from the University of NSW and part of the international team said the discovery pointed the way to the existence of planets that could be suitable for life.
Three planets with masses ranging from 5.3 to 24.9 Earth masses were found orbiting the star 61 Virginis, which is 28 light years from Earth in the constellation of Virgo.
Neptune has a mass 17 times that of the Earth.
The findings for 61 Virginis are to be published in The Astrophysical Journal.
"These planets are particularly exciting," Prof Tinney said.
"It looks like there may be many Sun-like stars nearby with planets of about that mass. They point the way to even smaller planets that could be rocky and suitable for life."
The fourth planet was a Jupiter-mass planet orbiting the star 23 Librae which is 84 light years away in the constellation of Libra.
Another planet was found around this star in 2006.
The new planet has a 14-year orbit, similar to Jupiter, which has a 12-year orbit.
To find the planets, the astronomers used a technique which measures how stars are tugged around by their planet's gravity.
Dr Paul Butler of the Carnegie Institute of Washington said there was a tremendous advantage to be gained from combining data from the two world-class observatories.
"It's clear that we'll have an excellent shot at identifying potentially habitable planets around the very nearest stars within just a few years."