High Accuracy Radial Velocity Planet Searcher

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

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. The first light was achieved in February 2003. 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 observatory. It is a second-generation radial-velocity spectrograph, based on experience with the ELODIE and CORALIE instruments.^[1]

Characteristics

HARPS can attain a precision of 0.97 m/s (3.5 km/h),^[2] with an effective precision of the order of 30 cm s⁻¹,^[3] making it one of only two instruments worldwide with such accuracy.^[4] 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.^[5] The precision and sensitivity of the instrument is such that it incidentally produced the best available measurement of the thorium spectrum.^[6] Planet-detection is in some cases limited by the seismic pulsations of the star observed rather than by limitations of the instrument.^[7]

The principal investigator on 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 exoplanet orbiting a normal star, and two super-Earths whose orbits lie in the star's habitable zone.^[8]

It was initially used for a survey of a thousand stars.

Since October 2012 the HARPS spectrograph has the precision to detect a new category of planets: Habitable super-Earths. This sensitivity was expected from simulations of stellar intrinsic signals, and actual observations of planetary systems. Currently, HARPS can detect habitable super-Earth only around low-mass stars as these are more affected by gravitational tug from planets and have habitable zones close to the host star.^[9]

Planets discovered by HARPS

A decade of discoveries from HARPS^[10]

HARPS spectrograph

HARPS spectrograph detail

Animation of HD 10180 with its planetary system consisting of seven planets (b–h) discovered by HARPS

• This is not a complete list.

See also

ESO 3.6-metre telescope is home to the world's foremost exoplanet hunter, HARPS.^[11]

Similar instruments:

• HARPS-N is a copy of this instrument installed in the northern hemisphere in 2012.
• Fiber-optic Improved Next-generation Doppler Search for Exo-Earths, operating at Lick observatory since 2009
• CORALIE spectrograph is a similar instrument also in La Silla,
• SOPHIE échelle spectrograph is a similar instrument.
• ELODIE spectrograph is the precursor instrument.
• Anglo-Australian Planet Search or AAPS is another southern hemisphere planet search program.
• ESPRESSO is a new-generation spectrograph for ESO's VLT.
• Automated Planet Finder, in commissioning at the Lick observatory

Space based detectors :

• COROT, spacecraft operating since 2007
• Kepler, operational since 2009
• Terrestrial Planet Finder, not funded, probably cancelled
• Space Interferometry Mission, construction halted in 2010
• Darwin, early studies for a multi-satellite mission

References

External links

• "HARPS Home Page". ESO. Retrieved 2009-04-25. 
• "The Exoplanet Hunter HARPS: unequalled accuracy and perspectives towards 1cm/s precision" (PDF). ESO.  (Contains list of discoveries from 2005 survey.)
• "New Planet-Hunting Technology Accelerates Discovery of Exo-Planets & Solar Systems". Daily Galaxy. 17 June 2008. 
• "Astronomers discover 4 new planets". NASA. 27 March 2007. Archived from the original on 22 April 2007. 

European Southern Observatory
Facilities	La Silla Observatory Llano de Chajnantor Observatory Paranal Observatory Space Telescope European Coordinating Facility
Telescopes	ALMA APEX ELT (under construction) ESO 3.6m EULER (national) NGTS (project) NTT MPG/ESO OWL (cancelled) VISTA VLT VST
Telescope instruments	ADONIS CORALIE ESPRESSO GROND HARPS KMOS MUSE PIONIER SPHERE VIMOS
Miscellany	Astronomy and Astrophysics ESO Hotel The Messenger Tim de Zeeuw
Book Category Portal:Astronomy/Space Commons

Exoplanet search projects
Ground-based	AAPS APF CORALIE EAPSNet ELODIE EPICS ESPRESSO FINDS Exo-Earths Geneva HARPS HARPS-N GPI HATNet HEK HiCIAO HIRES KELT LCES Magellan MARVELS MASCARA MEarth MicroFUN MINERVA MOA N2K NGTS NESSI OGLE OPSP PlanetPol Project 1640 PARAS SEEDS SETI SOPHIE SPECULOOS SPHERE SuperWASP Systemic TrES XO Telescope ZIMPOL/CHEOPS
Space missions	Past and current MOST (2003–present) SWEEPS (2006) COROT (2006–13) EPOXI (2008–13) Kepler (2009–present) KOI exoplanets Gaia (2013–present) Planned TESS (2018) CHEOPS (2018) James Webb Space Telescope (2018) PLATO (2026) WFIRST (mid-2020s) Proposed ATLAST EXCEDE FINESSE New Worlds Mission PEGASE Cancelled Darwin EChO Eddington Space Interferometry Mission Terrestrial Planet Finder
Detection methods Discoveries of exoplanets Lists of exoplanets