High Accuracy Radial Velocity Planet Searcher Explained

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 telescope. It is a second-generation radial-velocity spectrograph, based on experience with the ELODIE and CORALIE instruments.^[1]

Characteristics

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

It was initially used for a survey of one-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, the 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.^[6]

Discoveries

This is an incomplete list of exoplanets discovered by the HARPS. The list is sorted by the date of the discovery's announcement. As of December 2017, the list contains 134 exoplanets.

	10 February 2004
	25 August 2004
	22 March 2005
	22 March 2005
	22 March 2005
	30 March 2005
	30 March 2005
	8 September 2005
	12 October 2005
	25 January 2006
	18 May 2006
	18 May 2006
	18 May 2006
	14/18 August 2006
	2 April 2007
	6 April 2007
	6 April 2007
	6 April 2007
	23 April 2007
	23 April 2007
	7 August 2007
	27 June 2008
	27 June 2008
	27 June 2008
Gliese 176 b^[7]	4 September 2008
	26 October 2008
	26 October 2008
	26 October 2008
HD 131664 b^[8]	26 October 2008
	26 October 2008
	26 October 2008
	9 December 2008
	9 December 2008
	9 December 2009
	9 December 2009
	9 December 2009
	3 February 2009
	3 February 2009
	21 April 2009
	19 October 2009
	16 December 2009
	16 December 2009
HD 5388 b^[9]	16 December 2009
	16 December 2009
	16 December 2009

	29 December 2009
	29 December 2009
	29 December 2009
	29 December 2009
	29 December 2009
	5 October 2010
	5 October 2010
	5 October 2010
	6 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	17 December 2010
	23 November 2010
	23 November 2010
	23 November 2010
	23 November 2010
	23 November 2010
	23 November 2010
	23 November 2010
	1 July 2011
	1 July 2011
	1 July 2011
	1 July 2011
	8 July 2011
	8 July 2011
	8 July 2011
	8 July 2011
	17 August 2011
	17 August 2011
	17 August 2011
	17 August 2011
	17 August 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011

	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	12 September 2011
	21 November 2011
	5 April 2012
	5 April 2012
	22 June 2012
	29 June 2012
	29 June 2012
	29 June 2012
	6 September 2012
	6 September 2012
	25 June 2013
	25 June 2013

See also

Similar instruments:

• HARPS-N is a copy of this instrument installed in the northern hemisphere in 2012.
• HARPS3 is an updated design of this instrument that will be installed on an upgraded and roboticised Isaac Newton Telescope, in 2024.
• Fiber-optic Improved Next-generation Doppler Search for Exo-Earths, operating at Lick observatory since 2009
• 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, at the Lick observatory, commissioned in 2013.
• CAFE (Calar Alto Fibre-fed Echelle spectrograph) installed on the Calar Alto Observatory's 2.2-metre telescope in 2014, and the CARMENES mounted on the 3.5-metre telescope in 2016.
• EXPRES is a third generation radial velocity spectrograph that is planned to be installed on the Lowell Discovery Telescope.

Space based detectors :

• CoRoT, spacecraft operating since 2007
• Kepler space telescope, operational until 2018
• Terrestrial Planet Finder, cancelled
• Space Interferometry Mission, construction halted in 2010
• Darwin, early studies for a multi-satellite mission

External links

• • Web site: HARPS Home Page . . 25 April 2009.
• Web site: The Exoplanet Hunter HARPS: unequalled accuracy and perspectives towards 1 cm/s precision . . 2008-10-19-->. (Contains list of discoveries from 2005 survey.)
• Web site: New Planet-Hunting Technology Accelerates Discovery of Exo-Planets & Solar Systems . Daily Galaxy . 17 June 2008 . 2008-10-19-->,19 October 2008 . https://web.archive.org/web/20081007071337/http://www.dailygalaxy.com/my_weblog/2008/06/new-nasa-techno.html . 7 October 2008 . dead .
• Web site: Astronomers discover 4 new planets . . 27 March 2007 . https://web.archive.org/web/20070422214015/http://planetquest.jpl.nasa.gov/news/harps4NewPlanets.cfm . 22 April 2007 . dead .

Notes and References

1. Setting New Standards With HARPS. ESO Messenger. 114. 20. 2003. 2003Msngr.114...20M. 9. Mayor . M.. Pepe . F.. Queloz . D.. Bouchy . F.. Rupprecht . G.. Lo Curto . G.. Avila . G.. Benz . W.. Bertaux . J.-L.. Bonfils . X.. Dall . Th.. Dekker . H.. Delabre . B.. Eckert . W.. Fleury . M.. Gilliotte . A.. Gojak . D.. Guzman . J. C.. Kohler . D.. Lizon . J.-L.. Longinotti . A.. Lovis . C.. Megevand . D.. Pasquini . L.. Reyes . J.. Sivan . J.-P.. Sosnowska . D.. Soto . R.. Udry . S.. Van Kesteren . A..
2. News: 32 planets discovered outside solar system - CNN.com . CNN . 4 May 2010 . 19 October 2009.
3. Book: http://www.eso.org/sci/facilities/lasilla/instruments/harps/science/papers/6269-25.pdf . 2006SPIE.6269E..0PL . 14 September 2011 . 10.1117/12.669991 . 120961535 . The exoplanet hunter HARPS: Unequalled accuracy and perspectives toward 1 cm s^-1precision . Ground-based and Airborne Instrumentation for Astronomy . 2006 . McLean . Ian S. . Lovis . Christophe . Pepe . Francesco . Bouchy . François . Lo Curto . Gaspare . Mayor . Michel . Pasquini . Luca . Queloz . Didier . Rupprecht . Gero . Udry . Stéphane . Zucker . Shay . Proceedings of SPIE . 6269 . 62690P . Masanori . Iye .
4. Asteroseismology of solar-type stars: particular physical effects. Carrier. Journal of Physics: Conference Series. 118. 2008. 10.1088/1742-6596/118/1/012047. Eggenberger. P. Leyder. J-C. 012047. 1. 2008JPhCS.118a2047C . free.
5. 10.1051/0004-6361/200912172 . 2009A&A...507..487M . . 507 . 1 . 2009 . 487–494 . Mayor . Michel . Bonfils . Xavier . Forveille . Thierry . Delfosse . Xavier . Udry . Stéphane . Bertaux . Jean-Loup . Beust . Hervé . Bouchy . François . Lovis . Christophe . Pepe . Francesco . Perrier . Christian . Queloz . Didier . Santos . Nuno C. . The HARPS search for southern extra-solar planets, XVIII. An Earth-mass planet in the GJ 581 planetary system . 0906.2780 . 3 . 2983930 . dead . https://web.archive.org/web/20090521052641/http://obswww.unige.ch/~udry/Gl581_preprint.pdf . 21 May 2009 .
6. 2016Natur.536..437A. A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature. 536. 7617. 437–440. Anglada-Escudé. Guillem. Amado. Pedro J.. Barnes. John. Berdiñas. Zaira M.. Butler. R. Paul. Coleman. Gavin A. L.. de la Cueva. Ignacio. Dreizler. Stefan. Endl. Michael. Giesers. Benjamin. Jeffers. Sandra V.. Jenkins. James S.. Jones. Hugh R. A.. Kiraga. Marcin. Kürster. Martin. López-González. María J.. Marvin. Christopher J.. Morales. Nicolás. Morin. Julien. Nelson. Richard P.. Ortiz. José L.. Ofir. Aviv. Paardekooper. Sijme-Jan. Reiners. Ansgar. Rodríguez. Eloy. Rodríguez-López. Cristina. Sarmiento. Luis F.. Strachan. John P.. Tsapras. Yiannis. Tuomi. Mikko. Mathias . Zechmeister. 3. 2016. 1609.03449. 10.1038/nature19106. 27558064. 4451513.
7. has a shorter period.
8. This is an M sin i brown dwarf.
9. This is a brown dwarf.