The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision
echelle
An echelle grating (from French ''échelle'', meaning "ladder") is a type of diffraction grating characterised by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffract ...
planet-finding
spectrograph
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
installed in 2002 on the
ESO's 3.6m telescope at
La Silla Observatory
La Silla Observatory is an astronomy, astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are located at the site and are partly maintained by ESO. The obse ...
in
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
. The
first light was achieved in February 2003. HARPS has discovered over 130
exoplanet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...
s to date, with the first one in 2004, making it the most successful planet finder behind the
Kepler space observatory
The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbit ...
. It is a second-generation
radial-velocity spectrograph, based on experience with the
ELODIE and
CORALIE instruments.
Characteristics
The HARPS can attain a precision of 0.97 m/s (3.5 km/h),
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
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high me ...
lamp are observed simultaneously using two identical
optic fibre
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means t ...
feeds, and to careful attention to mechanical stability: the instrument sits in a vacuum vessel which is temperature-controlled to within 0.01 kelvins. 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 the HARPS is
Michel Mayor
Michel Gustave Édouard Mayor (; born 12 January 1942) 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 o ...
who, along with
Didier Queloz
Didier Patrick Queloz (; born 23 February 1966) is a Swiss astronomer. He is the Jacksonian Professor of Natural Philosophy at the University of Cambridge, where he is also a fellow of Trinity College, Cambridge, as well as a professor at the ...
and
Stéphane Udry
Stéphane Udry (born 1961 in Sion, Switzerland) is an astronomer at the Geneva Observatory 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 t ...
, have used the instrument to characterize the
Gliese 581 planetary system
Gliese 581 () is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is t ...
, home to one of the
smallest known exoplanets orbiting a normal star, and two
super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively.
The term "super-Earth" refers only to ...
s whose orbits lie in the star's
habitable zone
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kas ...
.
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.
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.
;Notes:
* (a) — M ''sin i''
brown dwarf
Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...
* (b) — brown dwarf
* (c) — shorter period
Gallery
File:The HELIOS instrument at the ESO 3.6-metre telescope in Chile.jpg, HELIOS instrument installed to feed sunlight via fibre optics to the HARPS
File:A decade of discoveries from HARPS.jpg, A decade of discoveries from HARPSHD 10180
HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and ...
with its seven planets
See also
Similar instruments:
*
HARPS-N
HARPS-N, the ''High Accuracy Radial velocity Planet Searcher for the Northern hemisphere'' is a high-precision radial-velocity spectrograph, installed at the Italian Telescopio Nazionale Galileo, a 3.58-metre telescope located at the Roque de los ...
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.
*
, operating at Lick observatory since 2009
*
Anglo-Australian Planet Search
The 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 3.9-metre Anglo-Australian Telescope (AAT) of the Anglo-Australian Observatory in Austral ...
or ''AAPS'' is another southern hemisphere planet search program.
*
ESPRESSO
Espresso (, ) is a coffee-brewing method of Italian origin, in which a small amount of nearly boiling water (about ) is forced under of pressure through finely-ground coffee beans. Espresso can be made with a wide variety of coffee beans and ...
is a new-generation spectrograph for
ESO
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ...
's
VLT.
*
Automated Planet Finder
The Automated Planet Finder (APF) Telescope a.k.a. Rocky Planet Finder, is a fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA.Steven S. Vogt et al., APF - ...
, 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 The EXtreme PREcision Spectrograph (EXPRES) is an optical fiber fed echelle instrument designed and built at the Yale Exoplanet Laboratory to be installed on the 4.3-meter Lowell Discovery Telescope operated by Lowell Observatory. It has a goal t ...
is a third generation radial velocity spectrograph that is planned to be installed on the
Lowell Discovery Telescope
The Lowell Discovery Telescope (LDT), formerly the Discovery Channel Telescope (DCT), is a aperture telescope owned and operated by Lowell Observatory. The LDT was built at a dark sky site in the Coconino National Forest near Happy Jack, Arizo ...
.
Space based detectors :
*
COROT
CoRoT (French: ; English: Convection, Rotation and planetary Transits) was a space telescope mission which operated from 2006 to 2013. The mission's two objectives were to search for extrasolar planets with short orbital periods, particularly th ...
, spacecraft operating since 2007
*
Kepler
Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws o ...
, operational since 2009
*
Terrestrial Planet Finder
The Terrestrial Planet Finder (TPF) was a proposed project by NASA to construct a system of space telescopes for detecting extrasolar terrestrial planets. TPF was postponed several times and finally cancelled in 2011. There were two telescope ...
, not funded, probably cancelled
*
Space Interferometry Mission
The Space Interferometry Mission, or SIM, also known as SIM Lite (formerly known as SIM PlanetQuest), was a planned space telescope proposed by the U.S. National Aeronautics and Space Administration (NASA), in conjunction with contractor Northro ...
, construction halted in 2010
*
Darwin, early studies for a multi-satellite mission
References
External links
*
*
* ''(Contains list of discoveries from 2005 survey.)''
*
*
{{Exoplanet search projects
Astronomical instruments
Telescope instruments
Exoplanet search projects
Spectrographs
European Southern Observatory
Articles containing video clips