October 19, 2009

Astronomers Discover 32 New Exoplanets

Recent discoveries by astronomers have brought the official number of planets outside of our solar system to over 400.

The team that constructed the High Accuracy Radial Velocity Planet Searcher (HARPS) reported the discovery of 32 new planets outside our galaxy.

HARPS is a spectrograph that is attached to the European Southern Observatory's telescope in La Silla, Chile.

Using the spectrograph, scientists are not able to gather images of planets, but they are able to make observations based on gravitational pull that can help them conclude the planets' size and mass.

Over the past five years, HARPS has discovered more than 75 of the roughly 400 known exoplanets.

In 2003, Michel Mayor, from the Geneva Observatory, led a consortium to build HARPS. In return, the consortium was given 100 nights per year during a five-year period to make observations.

In 2004, the HARPS team found the first super-Earth; in 2006, they found the trio of Neptunes around HD 69830l; in 2007, they discovered Gliese 581d, the first super Earth in the habitable zone of a small star; and earlier this year they found the lightest exoplanet around a normal star, Gliese 581e.

"These observations have given astronomers a great insight into the diversity of planetary systems and help us understand how they can form," team member Nuno Santos said in a statement.

"I'm pretty confident that there are Earth-like planets everywhere," said Stephane Udry of the University of Geneva.

"Nature doesn't like a vacuum. If there is space to put a planet there, there will be a planet there."


Image Caption: On October 19, 2009, the team who built the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for ESO's 3.6-meter telescope, reported on the incredible discovery of some 32 new exoplanets, cementing HARPS's position as the world's foremost exoplanet hunter. One of these is surrounding the star Gliese 667 C, which belongs to a triple system. The 6 Earth-mass exoplanet circulates around its low-mass host star at a distance equal to only 1/20th of the Earth-Sun distance. The host star is a companion to two other low-mass stars, which are seen here in the distance. Credit: ESO/L. Calçada


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