Very Small Exoplanet Around Red Dwarf

One of the smallest planets ever found in another solar system was discovered by astronomers at the European Southern Observatory in northern Chile, the observatory announced.

A team of French and Swiss astronomers said they detected the small exoplanet -- a planet orbiting a star other than the sun -- orbiting the red dwarf star Gl 581 in the Libra constellation, 20.5 light-years away from Earth.

While the star has a mass of only one-third of the sun, the exoplanet is roughly as large as Neptune, which is 17 times larger than Earth.

"Our finding possibly means that planets are rather frequent around the smallest stars," said Xavier Delfosse of the Grenoble Astrophysics Laboratory in France.

"It certainly tells us that red dwarfs are ideal targets for the search for exoplanets," said Delfosse in a statement.

The discovery was made using the HARPS spectrograph at the European Southern Observatory, located at La Silla, about 400 kilometers (250 miles) north of Santiago.

Of some 200 red dwarf stars studied, only two have been shown to have exoplanets in their orbits.

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It travels in an orbit six million kilometers (3.7 million miles) away from the star, and takes 5.4 days to complete its orbit.

Mercury, the closest planet to the sun in our own solar system, is 58 million kilometers (36 million miles) from the sun and takes 88 days for one revolution.

That close to its host star, the planet is probably extremely hot, around 150 degrees C (302 F), the observatory said.

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