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Thursday, 16 August, 2001, 16:42 GMT 17:42 UK
Planet hunt pays off
An artist's impression of planets in other solar systems
An artist's impression of planets in other solar systems. Image: PParc
A solar system much like our own could be sitting on our cosmic doorstep.

US scientists have found evidence that more than one planet is orbiting a star called 47 Ursae Majoris a mere 50 light years away from Earth.

The planet spotters said they are likely to find signs of even more planets as instruments become more sensitive and sky surveys become more comprehensive.

Now the scientists are pushing for funds to develop new telescopes that do nothing but look for planets orbiting nearby stars.

Near neighbours

A team of top planet hunters said today they have strong evidence that more than one planet is orbiting a star called 47 Ursae Majoris.

It's heartwarming to find a planetary system that finally reminds us of our solar system

Debra Fischer, planet hunter

The yellow type star is similar to our Sun and was already known to have a huge planet, twice the mass of Jupiter, orbiting it.

Now Debra Fischer and Geoffrey Marcy from the University of California at Berkeley working with Paul Butler of the Carnegie Institution of Washington have spotted another planet in a more distant orbit around the same star.

"For the first time we have detected two planets in nearly circular orbits around the same star," said Dr Fischer. "Most of the 70 planets people have found to date are in bizarre solar systems, with short periods and eccentric orbits close to the star."

Watch the wobble

The astronomers can't see the planet directly but infer its presence by watching for tiny wobbles in the star at the heart of the target solar system. More sensitive instruments made it possible to detect smaller wobbles and the presence of more planets.

THe surface of planet Jupiter
The new planet is smaller than Jupiter

The researchers estimate that the new planet is barely three-quarters the size of Jupiter.

To make their observations the scientists used the three and 0.6 metre telescopes at the University of California's Leck Observatory.

Now the team is pushing for cash to build a telescope that concentrates solely on watching the skies for evidence of more planets.

Significantly Dr Fischer and her colleagues said the new planet could be much further away from the central star and might imply that its solar system is dotted with planets and resembles ours.

"We've found planets in small orbits and wacky eccentric orbits," she said. "With 47Ursae Majoris, it's heartwarming to find a planetary system that finally reminds us of our solar system."

The star 47 Ursae Majoris is one of 100 that Dr Marcy and Dr Butler picked out in 1987 as possible systems supporting extrasolar planets.

See also:

27 Apr 01 | Sci/Tech
Barren world of stars
09 May 01 | Sci/Tech
Star 'eats' a planet
07 Aug 00 | Sci/Tech
Nine new planets found
21 Apr 99 | Sci/Tech
Is anybody out there?
10 Feb 99 | Sci/Tech
Hubble spies planet 'nurseries'
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