Extrasolar planet
hideAn extrasolar planet, or exoplanet, is a planet beyond our Solar System, orbiting a star other than our Sun. As of June 2009[update], 353 exoplanets are listed in the Extrasolar Planets Encyclopaedia. The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most announced exoplanets are massive gas giant planets thought to resemble Jupiter, but this is a selection effect (bias) due to limitations in detection technology. Projections based on recent detections of much smaller worlds suggest that lightweight, rocky planets will eventually be found to outnumber extrasolar gas giants.
Extrasolar planets became a subject of scientific investigation in the mid-19th century. Many astronomers supposed that such planets existed, but they had no way of knowing how common they were or how similar they might be to the planets of our Solar System. The first confirmed radial velocity detection was made in 1995, revealing a gas giant planet in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has tended to increase on an annual basis since then. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life.
Currently Gliese 581 d, the fourth planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits within the habitable zone surrounding its star. Although initial measurements suggested that Gliese 581 d resided outside the so-called "Goldilocks Zone", additional measurements place it firmly within.
For more information about Extrasolar planet, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with extrasolar planets
Discovery of a Retrograde or Highly Tilted Extrasolar Planet
Nov 18, 2009 |
4.8 / 5 (6) |
1
Astronomers have found that the extrasolar planet HAT-P-7b has a retrograde or highly tilted orbit. Studying such planets is important in understanding the diversity of planetary systems and assessing current ...
Search results for extrasolar planets
Beaming in on Warm Dense Matter (w/ Video)
1hour ago |
5 / 5 (1) |
0
(PhysOrg.com) -- The Neutralized Drift Compression Experiment II (NDCX-II) now under construction at Berkeley Lab will deliver a high-current pulse of lithium ions to a foil target almost simultaneously, momentarily heating ...
Astronomers Find Super-Earth Using Amateur, Off-the-Shelf Technology (w/ Video)
Dec 16, 2009 |
5 / 5 (18) |
10
(PhysOrg.com) -- Astronomers announced today that they have discovered a "super-Earth" orbiting a red dwarf star 40 light-years from Earth. They found the distant planet with a small fleet of ground-based ...
Icy moons of Saturn and Jupiter may have conditions needed for life
Dec 15, 2009 |
4.8 / 5 (15) |
0
(PhysOrg.com) -- Scientists once thought that life could originate only within a solar system's "habitable zone," where a planet would be neither too hot nor too cold for liquid water to exist on its surface. ...
First Direct Imaging of a Young Binary System
Dec 15, 2009 |
4.9 / 5 (16) |
2
(PhysOrg.com) -- A team of astronomers from The Graduate University for Advanced Studies, the National Astronomical Observatory of Japan, and other universities have captured the first direct image of a young ...
Fossils on the Edge of Forever
Space & Earth / Earth Sciences
Dec 14, 2009 |
4.9 / 5 (10) |
0
Astrobiologists have not yet found alien life on other planets. But the fossil record has evidence of aliens of another sort: the Ediacarans that lived on Earth millions of years ago.
NASA Launches Web Site for Teenagers That Want More Class
Space & Earth / Space Exploration
Dec 14, 2009 |
3.5 / 5 (2) |
0
(PhysOrg.com) -- NASA has launched a new Web site created specifically for teenagers that provides teens access to current NASA spacecraft data for use in school science projects, allows them to conduct real experiments with ...
Scientist uncovers relics of ancient cosmos
Space & Earth / Space Exploration
Dec 14, 2009 |
4.5 / 5 (18) |
3
(PhysOrg.com) -- A University of Manchester scientist, working as part of an international team, has uncovered an unexpectedly rich trove of relicts from the ancient cosmos.
Born in beauty: Proplyds in the Orion Nebula (w/ Video)
Dec 14, 2009 |
4.8 / 5 (9) |
1
(PhysOrg.com) -- A collection of 30 never-before-released images of embryonic planetary systems in the Orion Nebula are the highlight of the longest single Hubble Space Telescope project ever dedicated to ...
New planet discoveries suggest low-mass planets are common around nearby stars (w/ Video)
Dec 14, 2009 |
4.8 / 5 (17) |
14
(PhysOrg.com) -- An international team of planet hunters has discovered as many as six low-mass planets around two nearby Sun-like stars, including two "super-Earths" with masses 5 and 7.5 times the mass of ...
'Extreme' genes shed light on origins of photosynthesis
Dec 11, 2009 |
5 / 5 (3) |
1
(PhysOrg.com) -- While most school children understand that green plants photosynthesize, absorb carbon dioxide and produce oxygen, few people consider the profound global-scale effects that photosynthesis has had on Earth. ...
List of search results for extrasolar planets
