Europeans may have found planet slightly larger than Earth

William Atkins
Thursday, 26 August 2010 00:47

Science - Space

A team of astronomers from France, Germany, Portugal, and Switzerland has found a planetary system around the star HD 10180, which is only 127 light-years from Earth. The system is thought to contain a planet that is only 1.4 times larger than Earth.

 

If this planet is confirmed to be only 1.4 times larger than Earth, it would be the smallest exosolar planet, or exoplanet, so far discovered. An exoplanet is a planet that is orbiting a star other than our local star, the Sun.

The planetary system found orbiting HD 10180 contains five planets, but there is a strong indication that two more planets are also present.

If the final two planets are confirmed, then this would be the largest planetary system discovered so far (other than ours with eight planets).

HD 10180 is a star found in the southern constellaton of Hydrus. The star has a mass that is only about 6% the mass of our Sun.

Most of the planets have masses that are minimally 12 to 25 times the mass of Earth.

Five of them, HD 10180c, HD 10180d, HD 10180e, HD 10180f, and HD 10180g, are of comparable size to our planet Neptune. They consist of ice and rocks, with a solid core. A layer of bas, probably hydrogen and helium, is found above the core.

They orbit their star at approximate distances of 0.06, 0.13, 0.27, 0.49 and 1.42 astronomical units (AU), respectively (c, d, e, f, and g) where 1 AU is the average distance between the Sun and the Earth (about 93 million miles, or 150 million kilometers).

Page two continues with information on a possible sixth and seventh planet.