New technique could find more, smaller planets
Date: Friday, October 25 @ 00:06:41 CDT
Topic: 3. Space News
A new planet has been discovered using a pioneering technique.
The method could reveal the presence of worlds the size of Earth in other star systems.
It uses patterns created in the dust surrounding a star to reveal the presence of a planet that could be as small as Earth.
About 100 planets have so far been discovered beyond our Solar System, in most cases by measuring the way their gravity effects the parent star. This is because a star's bright glare makes it impossible to view planets directly using current technology.
A newer technique looks for the way planets slightly dim the light of a star when passing in front of it. But both methods can only detect giant gaseous planets the size of Jupiter or bigger, while smaller rocky planets like Earth or Mars remain hidden.
This could now change thanks to a completely new way of detecting extra-solar planets developed by US astronomers at the University of Rochester in New York State. The technique also allows the detection of planets with very wide orbits, whose effects on the parent star could only be observed over hundreds of years.
The new planet orbits the star Epsilon Eridani, a close neighbour of the Sun's only 10 light years from Earth.
It is one of the smallest extra-solar planets yet discovered, with a mass roughly a tenth that of Jupiter, and has by far the longest and widest orbit of any world found outside the Sun's family.
Traditional planet-detection methods would not have revealed the planet, tentatively named Epsilon Eridani C.
Dr Alice Quillen, Assistant Professor of Physics and Astronomy at Rochester, said: "We're very excited because this will open up the possibility of finding planets that we'd probably never detect just looking at the parent star. We can confirm the presence of certain planets in five years instead of the two centuries it would otherwise take."
Story filed: 19:55 Wednesday 23rd October 2002
http://www.ananova.com/news/story/sm_695539.html?menu=news.scienceanddiscovery
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