High Accuracy Radial Velocity Planet Searcher

The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile.

HARPS has discovered over 130 exoplanets to date, with the first one in 2004, making it the most successful planet finder behind the Kepler space telescope.

[citation needed] This is due to a design in which the target star and a reference spectrum from a thorium lamp are observed simultaneously using two identical optic fibre feeds, and to careful attention to mechanical stability: the instrument sits in a vacuum vessel which is temperature-controlled to within 0.01 kelvins.

[4] The principal investigator on the HARPS is Michel Mayor who, along with Didier Queloz and Stéphane Udry, have used the instrument to characterize the Gliese 581 planetary system, home to one of the smallest known exoplanets orbiting a normal star, and two super-Earths whose orbits lie in the star's habitable zone.

[citation needed] Since October 2012 the HARPS spectrograph has the precision to detect a new category of planets: habitable super-Earths.

Montage of the HARPS spectrograph and the 3.6m telescope at La Silla. The upper left shows the dome of the telescope, while the upper right illustrates the telescope itself. The HARPS spectrograph is shown in the lower image during laboratory tests. The vacuum tank is open so that some of the high-precision components inside can be seen
ESO 3.6-metre telescope is home to the world's foremost exoplanet hunter, HARPS. [ 9 ]