High Accuracy Radial velocity Planet Searcher
HARPS (High Accuracy Radial velocity Planet Searcher ) is an échelle spectrograph on the 3.6-meter ESO telescope at La Silla Observatory in Chile. It serves the high precision measurement of the radial velocity of stars, and thus the discovery of exoplanets. With an accuracy of about 1 m / s HARPS is one of the most accurate instruments for this purpose. HARPS was developed by a consortium led by the Observatoire de Genève and 2002 installed at La Silla; first measurements were made in 2003. 's sister instrument HARPS - N for the northern sky went Telescopio Nazionale Galileo in 2012 on operation.
HARPS has discovered until October 2009 75 exoplanets ( candidates ) and thus an essential part of all known exoplanets. In addition, the instrument for the detection of the majority of known exoplanets is characterized with a mass of less than 20 Earth masses responsible (as of end of 2009). Among the discoveries from HARPS include Alpha Centauri Bb and Gliese 581 d and Gliese 581 e, belonging to a system with four planetary companions. The discovery of exoplanets to unusually metal-poor stars by HARPS is a major challenge for existing theories of planet formation