Extra Solar Planets
by H Graem

The first confirmed discovery of extrasolar planets (planets around another star - also called exoplanets) occured in 1992. Radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of planets around a pulsar. In 1995, Michel Mayor and Didier Queloz of the University of Geneva announced the first definitive detection of an exoplanet orbiting an ordinary main-sequence star (51 Pegasi). This discovery was made at the Observatoire de Haute-Provence and ushered in the modern era of exoplanetary discovery.

Technological advances allowed astronomers to detect exoplanets indirectly by determining their gravitational influence on the motion of their parent stars. The planets are usually discovered by measuring the change in Doppler shift of the star's light, resulting from the star orbiting a common center of mass with a companion planet.

Several extrasolar planets were detected by observing the variation in a star's apparent luminosity as a planet passed or transited in front of it. The occasional transit of Venus across the sun is an example from our own Solar System.

At the end of 2007, a little over 220 exoplanets had been discovered around stars near the sun. Most of them are huge and hot gas planets (similar or larger in mass to Saturn or Jupiter) orbiting very close to their sun.

Given the current early stage in planet searching technology, this preponderance of giant planet discoveries in close solar orbit should not be surprising. These would be the most noticeable planetary bodies given the degree of sensitivity of the available instruments.

As sensitivity increases in the future and new methodologies become common, the average range in planet distance from the parent star should increase and the average observed planet size should decrease. Astronomers have recently discovered that terrestrial planets might form around many, if not most, of the nearby sun-like stars in our galaxy.

SOURCE: http://www.visions2200.com/SpaceExtraSolarPrime.html

John Whatmough's artwork has been used in many publications to depict an artist's concept of the current discoveries of extra solar planets. Extrasolar Visions images have appeared in Nova, Astronomy Magazine, Scientific American, and others. Visit his website here - The Image Portfolio

• Neptunian Exoplanets
• Neptunian Exoplanets images and animations
• Neptunian NASA Extrasolar Planets
• ESO HARPS Discovers Smallest Extrasolar Planet
• La Silla Observatory
• Hobby-Eberly Telescope Discoveries
• Keck Observatory
• Extrasolar Planets Encyclopaedia
• The Search for the Extrasolar Planets: A Brief History of the Search, the Findings and the Future Implications
• Hunting Planets Along the Milky Way
• Future American and European Planet Finding Missions
• Is That Tiny Dot a Planet?
• Planet Construction Zone at Nearby Star
• Planet Seen Outside Our Solar System
• NASA's Origins Program
• Where did we come from? Are we alone?
• Lightyears
• NASA JPL Planet Quest
• NASA JPL Space Interferometry Mission
• NASA JPL Terrestrial Planet Finder

NASA JPL Kepler

AUSTRALIAN BROADCASTING CORPORATION:

• 16 04 1999 - New Solar System Found
• 15 11 1999 - Gotcha! A planet's shadow provides proof
• 01 12 1999 - Planet hunters net another six
• 12 12 2000 - Australian telescope finds new planets
• 18 10 2001 - Planets found with Earth-like orbits
• 25 01 2002 - Jupiter: not so special after all
• 14 06 2002 - Planet hunters zero in on a system like ours
• 11 07 2002 - Astronomers discover 101st planet
• 29 11 2002 - Gas giant planets form quicker than thought
• 13 03 2003 - Dying planet being consumed by its sun
• 03 07 2003 - Found! A planetary system a lot like home
• 24 09 2003 - Study predicts trillions of planets
• 16 03 2004 - Furthest 'planet' found beyond Pluto
• 01 09 2004 - Found! Two planets in a class of their own
• 14 02 2005 - Smallest Exoplanet Found
• 02 05 2005 - This Blob is an Exoplanet

OTHER RESEARCH:

• Details and graphics of the new planets found with the Keck Telescope
• Extrasolar planets - Wikipedia Resource
• List of extrasolar planets
• List of extrasolar planet extremes
• List of unconfirmed extrasolar planets
• The Extrasolar Planets Encyclopaedia
• Other lists of extrasolar planets :
• California & Carnegie Planet Search Almanac 
• California & Carnegie Catalog of Nearby Exoplanets 
• Geneva Observatory Lists 
• Exoplanet Transit Database
• Transiting Planets (Frédéric Pont) 
• Debris Disk Database (ROE) 
• San Francisco State University's Extrasolar Planet Page
• Systemic - Characterizing extrasolar planetary systems

Visit Walter Myers's website here - Extrasolar Planets Discovered