HARPS sees HD 40307 planets: We have ability to find earth-type exoplanets

William Atkins
Tuesday, 17 June 2008 03:06

Science - Space

Astrophysicists have found, for the very first time, a trio of super-earth planets around a sun-like star.

Although these planets are too close to its star to support life as we know it, the use of the HARPS instrument on a Chilean telescope makes it well apparent that we have the ability to effectively search and find earth-like planets, and possibly earth-like life, out there in outer space.

The astrophysical team making this discovery is composed of Michel Mayor, Stéphane Udry, Didier Queloz, Christophe Lovis, and Francesco Pepe (Geneva Observatory, Geneva University, Switzerland); François Bouchy (Institut d'Astrophysique de Paris, France); Willy Benz and Christophe Mordasini (Physikalisches Institut, Bern University, Switzerland); and Jean-Loup Bertaux (Service d'aéronomie du CNRS, Université de Versailles Saint-Quentin, France).

They are excited about such a discovery because a planet similar in size to our own planet Earth, but circling about a star other than the Sun, has yet to be found. This discovery tells astronomers around the world that we can find earth-like planets.

Astronomers are looking for exosolar planets (exoplanets)--that is, planets orbiting stars other than the Sun--particularly, with sizes similar to Earth and with habitable zones about their host stars that could harbor some type of life.

Super-earth planets are defined as large, terrestrial, estrasolar planets that are more massive than planet Earth but less massive than planets Uranus or Neptune (which, each, is about fifteen times the mass of Earth).

The astronomers found the three planets orbiting about the star HD 40307. The three planets discovered by HARPS are 4.2, 6.7, and 9.4 times the mass of the Earth, and with periods of 4.3, 9.6, and 20.4 earth-days about the star, respectively (thus, from closest to furthest from the star).

They are called HD 40307a, HD 40307b, and HD 40307c, respectively.

The three planets were discovered using the HARPS (High Accuracy Radial velocity Planet Searcher) high-precision spectrograph on the 3.6-meter telescope at La Silla, Chile, which is operated by the European Organization for Astronomical Research in the Southern Hemisphere (European Southern Observatory, ESO).

An artist’s concept of the HD 40307 star and its three super-earth planets is found at Space.com.

Read comments from the astrophysics team making this important discovery in the field of astronomy. Please turn the page.