High Accuracy Radial Velocity Planet Searcher
Encyclopedia
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.
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 0.01 °K. 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.
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 known exoplanet
orbiting a normal star, and two super-Earth
s whose orbits lie in the star's habitable zone
.
It was initially used for a survey of a thousand stars.
In October 2009, the discovery of 32 additional exoplanets was announced by ESO, bringing the total to 75 exoplanets first observed by HARPS.
In August 2010, the discovery of several exoplanets was announced, including HD 10180
.
In September 2011, it was announced that 50 planets were discovered, including Super-Earth
s, in particular, HD 85512 b
, which lies just on the edge of the habitable zone.
Echelle grating
An echelle grating is a type of diffraction grating which is characterised by a relatively low groove density but is optimized for high diffraction orders. Echelle gratings are, like other types of diffraction grating, used in spectrometers and similar instruments, such as HARPS, and numerous...
spectrograph
Spectrograph
A spectrograph is an instrument that separates an incoming wave into a frequency spectrum. There are several kinds of machines referred to as spectrographs, depending on the precise nature of the waves...
installed in 2002 on ESO's 3.6m telescope at La Silla Observatory
La Silla Observatory
La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory organisation, and several others are partly maintained by ESO...
in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
. The first light was achieved in February 2003. It is a second-generation radial-velocity spectrograph, based on experience with the ELODIE and CORALIE
CORALIE spectrograph
The CORALIE spectrograph is an echelle type spectrograph used for astronomy. This instrument used with a telescope to measure star spectra for the Doppler effect to detect the presence of extrasolar planets by the radial velocity method...
instruments.
Characteristics
HARPS can attain a precision of 0.97 m/s (3.5 km/h), with an effective precision of the order of 30 cms-1, making it 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 thoriumThorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....
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 0.01 °K. 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
Asteroseismology
Asteroseismology also known as stellar seismology is the science that studies the internal structure of pulsating stars by the interpretation of their frequency spectra. Different oscillation modes penetrate to different depths inside the star...
of the star observed rather than by limitations of the instrument.
The principal investigator on HARPS is Michel Mayor
Michel Mayor
Dr. Michel G. E. Mayor is a Swiss astrophysicist and professor emeritus at the University of Geneva's Department of Astronomy. He formally retired in 2007, but remains active as a researcher at the Observatory of Geneva...
who, along with Didier Queloz
Didier Queloz
Didier Queloz is a Geneva-based astronomer with a prolific record in finding extrasolar planets. He is understudy to Michel Mayor.Didier Queloz was a Ph.D...
and Stéphane Udry
Stéphane Udry
Stéphane Udry is an astronomer at the University of Geneva in Switzerland, whose current work is primarily the search for extra-solar planets. He and his team, in 2007, discovered a possibly terrestrial planet in the habitable zone of the red dwarf star Gliese 581, approximately 20 light years...
have used the instrument to characterize the Gliese 581
Gliese 581
Gliese 581 is a red dwarf star with spectral type M3V, located 20.3 light years away from Earth in the constellation Libra. Its estimated mass is about a third of that of the Sun, and it is the 89th closest known star system to the Sun. Observations suggest that the star has at least six planets:...
system, home to the smallest known exoplanet
Gliese 581 e
Gliese 581 e or Gl 581 e is an extrasolar planet found around Gliese 581, an M3V red dwarf star approximately 20.5 light-years away from Earth in the constellation of Libra...
orbiting a normal star, and two super-Earth
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below the mass of the Solar System's gas giants. The term super-Earth refers only to the mass of the planet, and does not imply anything about the surface conditions or habitability...
s whose orbits lie in the star's habitable zone
Habitable zone
In astronomy and astrobiology, a habitable zone is an umbrella term for regions that are considered favourable to life. The concept is inferred from the empirical study of conditions favourable for Life on Earth...
.
It was initially used for a survey of a thousand stars.
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.| Planet Planet A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,... |
Date announced |
|---|---|
| HD 330075 b HD 330075 b HD 330075 b is an extrasolar planet approximately 164 light-years away in the constellation of Norma. This planet orbits the star HD 330075. It was discovered by the Geneva Extrasolar Planet Search team at ESO's La Silla Observatory using the HARPS spectrograph.The planet has a mass about three... |
10 February 2004 |
| Mu Arae c Mu Arae c Mu Arae e is one of the four extrasolar planets orbiting the star Mu Arae. Its discovery was announced on June 13, 2002. Mu Arae e is a gas giant at least 1.8 times as massive as Jupiter. The planet orbits at Jupiter-like distance at 5.235 AU.-References:... |
25 August 2004 |
| Gliese 876 d Gliese 876 d Gliese 876 d is an extrasolar planet approximately 15 light-years away in the constellation of Aquarius . The planet was the third planet discovered orbiting the red dwarf star Gliese 876. At the time of its discovery, the planet had the lowest mass of any known extrasolar planet apart from the... |
13 June 2005 |
| HD 93083 b HD 93083 b HD 93083 b is an extrasolar planet orbiting the star HD 93083 in Antlia constellation. It is probably much less massive than Jupiter, although only the minimum mass is known. The planet's mean distance from the star is about half that of Earth, and the orbit is slightly eccentric... |
2005 |
| HD 101930 b HD 101930 b HD 101930 b is an extrasolar planet orbiting the star HD 101930. It has a minimum mass a third of Jupiter's, nearly the same as Saturn's so it is thought to be a gas giant. It orbits the star closer than Mercury, and the orbit is slightly eccentric.... |
2005 |
| HD 102117 b HD 102117 b HD 102117 b is a planet that orbits the star HD 102117. The planet is a small gas giant a fifth the size of Jupiter. It orbits very close to its star, but not in a "torch orbit" like the famous 51 Pegasi b. It is one of the smallest extrasolar planets discovered so far.In 2004, the Anglo-Australian... |
2005 |
| HD 4308 b HD 4308 b HD 4308 b is a low-mass jovian exoplanet orbiting around HD 4308. The planet orbits very close to the star.... |
2005 |
| HD 69830 b HD 69830 b HD 69830 b is a Neptune-mass or Super-Earth mass extrasolar planet orbiting the star HD 69830. This planet is 10 times more massive than Earth, making it the least massive in the system. It also orbits quite close to its parent star and takes 82/3 days to complete an orbit.This is likely to be a... |
18 May 2006 |
| HD 69830 c HD 69830 c HD 69830 c is the 2nd planet orbiting HD 69830. This is likely to be a rocky planet, not a gas giant. If it had formed as a gas giant, it would have stayed that way.-References:... |
18 May 2006 |
| HD 69830 d HD 69830 d HD 69830 d is an extrasolar planet orbiting the orange dwarf star HD 69830 every 197 days. It is the outermost known planet in its planetary system and possibly lies within its habitable zone.-Orbit and mass:... |
18 May 2006 |
| Gliese 581 c Gliese 581 c Gliese 581 c or Gl 581 c is a planet orbiting the red dwarf star Gliese 581. It is the second planet discovered in the system and the third in order from the star. With a mass at least 5.6 times that of the Earth, it is classified as a super-Earth... |
23 April 2007 |
| Gliese 581 d Gliese 581 d Gliese 581 d or Gl 581 d is an extrasolar planet orbiting the star Gliese 581 approximately 20 light-years away in the constellation of Libra. It is the third planet discovered in the system and the fifth in order from the star.... |
23 April 2007 |
| HD 40307 b HD 40307 b HD 40307 b is an extrasolar planet orbiting the star HD 40307, located 42 light-years away in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the HARPS apparatus, in June 2008; it is the smallest of three "Super-Earths", planets... |
June 2008 |
| HD 40307 c HD 40307 c HD 40307 c is an extrasolar planet orbiting the star HD 40307, located 42 light-years away in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the HARPS apparatus, in June 2008... |
June 2008 |
| HD 40307 d HD 40307 d HD 40307 d is an extrasolar planet orbiting the star HD 40307, located 42 light-years from Earth in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the HARPS apparatus in June 2008. It is the most massive of the three known... |
June 2008 |
| Gliese 581 e Gliese 581 e Gliese 581 e or Gl 581 e is an extrasolar planet found around Gliese 581, an M3V red dwarf star approximately 20.5 light-years away from Earth in the constellation of Libra... |
April 2009 |
In October 2009, the discovery of 32 additional exoplanets was announced by ESO, bringing the total to 75 exoplanets first observed by HARPS.
In August 2010, the discovery of several exoplanets was announced, including HD 10180
HD 10180
HD 10180 is a solar-type star. A research team led by Christophe Lovis of the University of Geneva discovered that the star has at least five planets, and possibly as many as seven. It is 127 light-years away, in the southern constellation of Hydrus...
.
In September 2011, it was announced that 50 planets were discovered, including Super-Earth
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below the mass of the Solar System's gas giants. The term super-Earth refers only to the mass of the planet, and does not imply anything about the surface conditions or habitability...
s, in particular, HD 85512 b
HD 85512 b
HD 85512 b is an extrasolar planet orbiting the K-type star Gliese 370 approximately 36 light-years away in the constellation of Vela ....
, which lies just on the edge of the habitable zone.
See also
- Fiber-optic Improved Next-generation Doppler Search for Exo-EarthsFiber-optic Improved Next-generation Doppler Search for Exo-EarthsThe Fiber-Optic Improved Next-Generation Doppler Search for Exo-Earths is a radial-velocity spectrograph developed by Debra Fischer...
- CORALIE spectrographCORALIE spectrographThe CORALIE spectrograph is an echelle type spectrograph used for astronomy. This instrument used with a telescope to measure star spectra for the Doppler effect to detect the presence of extrasolar planets by the radial velocity method...
is a similar instrument also in La Silla, - SOPHIE échelle spectrographSOPHIE échelle spectrographThe SOPHIE échelle spectrograph is a high-resolution echelle spectrograph installed on the 1.93m reflector telescope at the Haute-Provence Observatory located in south-eastern France...
is a similar instrument. - ELODIE spectrographELODIE spectrographELODIE was an echelle type spectrograph installed at the Observatoire de Haute-Provence 1.93m reflector in south-eastern France for the . Its optical instrumentation was developed by André Baranne from the Marseille Observatory. The purpose of this instrument was extrasolar planet detection by the...
is the precursor instrument. - Anglo-Australian Planet SearchAnglo-Australian Planet SearchThe Anglo-Australian Planet Search or AAPS is a long-term astronomical survey started in 1998 and continuing to the present. It is being carried out on the 3.9m Anglo-Australian Telescope, AAT, of the Anglo-Australian Observatory in Australia. The purpose of this survey is to catalog planets around...
or AAPS is another southern hemisphere planet search program. - List of extrasolar planets
- ESPRESSOESPRESSOESPRESSO is a new-generation, high-resolution, fiber-fed and cross-dispersed echelle spectrograph for the visible wavelength range , for the European Southern Observatory's Very Large Telescope...
is a new-generation spectrograph for ESOESOESO, as a three-letter abbreviation, may stand for:* European Southern Observatory* Ensemble Studios Online* English Symphony Orchestra* Edmonton Symphony Orchestra* Executive Stock Options...
's VLTVLTVLT may stand for:* Very Large Telescope, a system of four large optical telescopes organized in an array formation, located in northern Chile...
. - Kepler (spacecraft)
- Terrestrial Planet FinderTerrestrial Planet FinderThe Terrestrial Planet Finder was a proposed project by NASA to construct a system of telescopes for detecting extrasolar terrestrial planets. TPF was postponed several times and finally cancelled...
- COROTCorotCorot may refer to:* Jean-Baptiste-Camille Corot, French landscape painter * COROT, a space mission with the dual aims of finding extrasolar planets and performing asteroseismology* COROT-7, a dwarf star in the Monoceros constellation...
- Space Interferometry MissionSpace Interferometry MissionThe Space Interferometry Mission, or SIM, also known as SIM Lite , was a planned space telescope developed by the U.S. National Aeronautics and Space Administration , in conjunction with contractor Northrop Grumman...
- Darwin (spacecraft)
- Automated Planet FinderAutomated Planet FinderThe Automated Planet Finder Telescope is a fully automated 2.4-meter optical telescope under construction at Lick Observatory designed to search for extrasolar planets in the range of five to twenty times the mass of the Earth. The instrument will examine 25 stars per night. Over a decade, the...