HARPS

The High Accuracy Radial velocity Planet Searcher (HARPS) is a high-precision echelle spectrograph installed in 2002 on ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. 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] one of only two instruments worldwide with such accuracy. This is thanks 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 very great attention to mechanical stability: the instrument sits in a vacuum vessel which is temperature-controlled to within 0.01C. The precision and sensitivity of the instrument is such that it incidentally produced the best available measurement of the thorium spectrum.^[1] Planet-detection is in some cases limited by the seismic pulsations of the star observed rather than by limitations of the instrument.^[3]

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 system, home to the smallest exoplanet orbiting a normal star, and two super-Earths whose orbits lie in the star's habitable zone.^[4]

It was initially used for a survey of a thousand stars^{[citation needed]}.

Planets Discovered by HARPS

This instrument has been used to discover 16 planetary objects in the southern hemisphere, including four multi-planet systems, as of May 2009.

In October 2009, the discovery of 32 additional exoplanets was announced by ESO,^[5] bringing the total to 75 exoplanets first observed by HARPS.^[2]

See Also

• • 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.

• List of extrasolar planets

References

• 1. ^ ^{a b} Mayor et al. (2003). "Setting New Standards With HARPS". ESO Messenger 114: 20. http://www.eso.org/sci/facilities/lasilla/instruments/harps/science/papers/harps_mess114.pdf.

  2. ^ ^{a b} "32 planets discovered outside solar system - CNN.com". CNN. 19 October 2009. http://www.cnn.com/2009/TECH/science/10/19/space.new.planets/index.html. Retrieved 4 May 2010.

  3. ^ Carrier et al.; Eggenberger, P; Leyder, J-C (2008). "Asteroseismology of solar-type stars: particular physical effects". Journal of Physics: Conference Series 118: 012047. doi:10.1088/1742-6596/118/1/012047. http://www.iop.org/EJ/article/1742-6596/118/1/012047/jpconf8_118_012047.pdf.

  4. ^ Mayor et al. (2009). "The HARPS search for southern extra-solar planets,XVIII. An Earth-mass planet in the GJ 581 planetary system". Astronomy and Astrophysics. http://obswww.unige.ch/~udry/Gl581_preprint.pdf.

  5. ^ http://www.eso.org/public/outreach/press-rel/pr-2009/pr-39-09.html

External Links

• "HARPS Home Page". ESO. http://www.eso.org/sci/facilities/lasilla/instruments/harps/index.html. Retrieved 2009-04-25.

• "The Exoplanet Hunter HARPS: unequalled accuracy and perspectives towards 1cm/s precision - contains list of discoveries from 2005 survey."]. ESO. http://www.eso.org/sci/facilities/lasilla/instruments/harps/science/papers/6269-25.pdf. Retrieved 2008-10-19.

• "New Planet-Hunting Technology Accelerates Discovery of Exo-Planets & Solar Systems". Daily Galaxy. http://www.dailygalaxy.com/my_weblog/2008/06/new-nasa-techno.html. Retrieved 2008-10-19.

• "Astronomers discover 4 new planets". NASA. http://planetquest.jpl.nasa.gov/news/harps4NewPlanets.cfm. Retrieved 2008-10-19.

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