Franck Marchis

Franck Marchis (born April 06, 1973 in Caen, France), astronomer and planetary scientist, is best-known for his discovery and characterization of multiple asteroids and its study of Io volcanism.

The asteroid 6639 Marchis was named in his honor on April 4th 2007.

Background

Marchis was born in France. He is currently an assistant research Astronomer at University of California at Berkeley a Principal Investigator at SETI Institute. He received his Ph.D. in 2000 from university of Toulouse, France in planetary science. Although his thesis was performed while living in several places: Mexico, France, Great-Britain; the main part of his studies were made while working at La Silla observatory in Chile for the European Southern Observatory, an intergovernmental organization aiming to develop astronomy in the southern hemisphere. He participated in the development of ovservations with the first adaptive optics system available to a large community (called ADONIS on the 3.6m telescope). He moved to California shortly after receiving his Ph.D. in November 2000 through a postdoctoral position at UC Berkeley.Since then he dedicates most of his activity monitoring Io's volcanism with the Keck-10m telescope and the support of CfAO, an NSF science and technology center. In 2003, he was hired as an assistant researcher to conduct his research more independently and expanded it to a broader field, but still based on high angular resolution capabilities. He has also taught on several occasions "The Planets" class at UC-Berkeley (Astro 12). He is associate astronomer at Observatoire de Paris, IMCCE. (ref [1] )

Discovery of companions of asteroids

Marchis exploited the high-resolution capabilities offered by adaptive optics from groundbased telescope to survey hundreds of main belt asteroids and Trojans.Together with his team, they announced the discovery of the first triple asteroid system in August 2005 (87 Sylvia), and the first measurement of a Trojan bulk-density in February 2006 (617 Patroclus). Both discoveries were published in Nature journal (ref [2] , [3] )

In July 2006, Marchis and his team announced the discovery of a moonlet companion around 624 Hektor using the Keck Laser guide star AO system (ref [4] ). This is the first multiple system in the L4 swarm and the first moonlet companion in the Trojan discovered.

The second triple system orbiting in the main-belt was discovered by the same team and announced in March 2007. Subsequent analysis of VLT-NACO images taken in Jan. 2004 revealed the presence of a second 6-km size moonlet orbiting around (45) Eugenia. Since 1999, this system was known to have a large moonlet, called Petit-Prince (~15 km) orbiting at 1200 km. ref [6]

Volcanic activity of Io

Using high imaging capability available on ground-based telescopes equipped with adaptive optics systems, F. Marchis and his team monitor and study the exotic volcanism of Io, Galilean satellite of Jupiter.In February 2001, they witnessed the most energetic eruption ever seen on the solar system. Surt volcano, located on the north hemisphere of Io, was then starting an extremely active eruption. The observed energy indicates the presence of a vigorous, high-temperature volcanic eruption. The kind of eruption to produce this thermal signature has incandescent fire fountains of molten lava which are kilometers high, propelled at great speed out of the ground by expanding gases, accompanied by extensive lava flows on the surface. The Surt eruption appears to cover an area of 1,900 square kilometers, which is larger than the city of Los Angeles and even larger than the entire city of London [5] .

References

[1] [http://www.sfaa-astronomy.org/lectures/lecturesdraw.php?lecdraw:gm:108 SFAA-Astronomy Lecture - Bio] [2] [http://www.nature.com/nature/journal/v436/n7052/full/nature04018.html Discovery of the First Triple Asteroid System, Nature, Aug. 2005] [3] [http://www.nature.com/nature/journal/v439/n7076/abs/nature04350.html A low density of 0.8 g cm-3 for the Trojan binary asteroid 617 Patroclus, Nature, Feb. 2006] [4] [http://cfa-www.harvard.edu/iauc/08700/08732.html IAU Circular 8732 Aug. 2006] [5] [http://www.keckobservatory.org/printer_friendly_with.php?id=54 EXCEPTIONALLY BRIGHT ERUPTION ON IO RIVALS LARGEST IN SOLAR SYSTEM] [6] [http://cfa-www.harvard.edu/iauc/08800/08817.html#Item1l Discovery of a second moonlet orbiting around (45) Eugenia]

External links

* [http://astro.berkeley.edu/~fmarchis/ Franck Marchis' homepage]
* [http://www.eso.org/outreach/press-rel/pr-2005/pr-21-05.html Rubble-Pile Minor Planet Sylvia and Her Twins ESO PR]
* [http://www.berkeley.edu/news/media/releases/2005/08/10_sylvia.shtml First triple asteroid system found, UC-Berkeley, PR]
* [http://www.berkeley.edu/news/media/releases/2006/02/01_patroclus.shtml Binary asteroid in Jupiter's orbit may be icy comet from solar system's infancy, UC-Berkeley PR]
* [http://www.sciam.com/article.cfm?chanID=sa003&articleID=000641C7-4EEC-12FA-8EEC83414B7F0000 Unique Triple Asteroid System Discovered, Scientific American]
* [http://space.newscientist.com/article.ns?id=dn7828 Solar system's first triple asteroid system found, NewScientist]
* [http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/08/11/MNGC1E61SV1.DTL Scientists discover asteroid with moons Tiny planetary system orbiting between Mars and Jupiter, San Francisco Chronicle, Aug. 11 2005]
[Category:American astronomers|Marchis, Franck] , [Multiple Asteroids]