Stéphane Udry
Encyclopedia
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
away in the constellation Libra
. He also led the observational team that discovered HD 85512 b
, another most promisingly habitable exoplanet.
in 1992, and spent two years at Rutgers University
in New Jersey
. Later, Udry returned to Geneva, and worked with Michel Mayor
, the discoverer of 51 Pegasi b
, the first extrasolar planet found revolving around a normal star
. In 2007, Udry was appointed full professor in the faculty of natural sciences at the University of Geneva.
of stars. Among them was Gliese 581 c
(announced April 25, 2007)which at the time, was the most likely candidate for habitability
of any extrasolar planet discovered so far. The planet was discovered by analyzing data obtained by the High Accuracy Radial Velocity Planet Searcher
(HARPS) on the European Southern Observatory
's 3.6 meter telescope at La Silla Observatory
in Chile
.
He was interviewed by Mat Kaplan on Planetary Radio
. Udry described a new instrument known as the Echelle Spectrography for Rocky Exoplanet and Stable Spectroscopic Observations, dubbed ESPRESSO, might allow astronomers to detect Earth-like planets within five to ten years from 2010.
An upgraded HARPS, of which Udry lead the observational team, found evidence that Gliese 581 d
might be more habitable (rather than c or g), and also detected another promising candidate: HD 85512 b
.
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
at the University of Geneva
University of Geneva
The University of Geneva is a public research university located in Geneva, Switzerland.It was founded in 1559 by John Calvin, as a theological seminary and law school. It remained focused on theology until the 17th century, when it became a center for Enlightenment scholarship. In 1873, it...
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, whose current work is primarily the search for extra-solar planets. He and his team, in 2007, discovered a possibly terrestrial planet
Terrestrial planet
A terrestrial planet, telluric planet or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun...
in the 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...
of the red dwarf
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
star 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:...
, approximately 20 light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....
away in the constellation Libra
Libra (constellation)
Libra is a constellation of the zodiac. Its name is Latin for weighing scales, and its symbol is . It is fairly faint, with no first magnitude stars, and lies between Virgo to the west and Scorpius to the east.-Notable features:]...
. He also led the observational team that discovered 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 ....
, another most promisingly habitable exoplanet.
Career
Udry earned a doctorate at the University of GenevaUniversity of Geneva
The University of Geneva is a public research university located in Geneva, Switzerland.It was founded in 1559 by John Calvin, as a theological seminary and law school. It remained focused on theology until the 17th century, when it became a center for Enlightenment scholarship. In 1873, it...
in 1992, and spent two years at Rutgers University
Rutgers University
Rutgers, The State University of New Jersey , is the largest institution for higher education in New Jersey, United States. It was originally chartered as Queen's College in 1766. It is the eighth-oldest college in the United States and one of the nine Colonial colleges founded before the American...
in New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
. Later, Udry returned to Geneva, and worked with 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...
, the discoverer of 51 Pegasi b
51 Pegasi b
51 Pegasi b , sometimes though unofficially named Bellerophon, is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus...
, the first extrasolar planet found revolving around a normal star
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
. In 2007, Udry was appointed full professor in the faculty of natural sciences at the University of Geneva.
Research
Udry's initial research concerned the dynamics of galaxies. His current work chiefly concerns the search for extra-solar planets by analyzing variations in the radial velocitiesRadial velocity
Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
of stars. Among them was 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...
(announced April 25, 2007)which at the time, was the most likely candidate for habitability
Planetary habitability
Planetary habitability is the measure of a planet's or a natural satellite's potential to sustain life. Life may develop directly on a planet or satellite or be transferred to it from another body, a theoretical process known as panspermia...
of any extrasolar planet discovered so far. The planet was discovered by analyzing data obtained by the High Accuracy Radial Velocity Planet Searcher
High Accuracy Radial Velocity Planet Searcher
The High Accuracy Radial velocity Planet Searcher 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...
(HARPS) on the European Southern Observatory
European Southern Observatory
The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...
's 3.6 meter 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...
.
He was interviewed by Mat Kaplan on Planetary Radio
Planetary Radio
Planetary Radio is a weekly 30-minute radio show devoted to space exploration and astronomy, hosted and produced by Mat Kaplan and The Planetary Society. Every week, it consists mostly of interviews and telephone-based conversations with a scientist, engineer, project manager, artist, a writer and...
. Udry described a new instrument known as the Echelle Spectrography for Rocky Exoplanet and Stable Spectroscopic Observations, dubbed ESPRESSO, might allow astronomers to detect Earth-like planets within five to ten years from 2010.
An upgraded HARPS, of which Udry lead the observational team, found evidence that 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....
might be more habitable (rather than c or g), and also detected another promising candidate: 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 ....
.