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.
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News tagged with exoplanets
Exoplanet atmospheres detected from Earth for the first time
Jan 14, 2009 |
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(PhysOrg.com) -- Transiting exoplanets are routinely detected when they pass in front of their parent star as viewed from the Earth, which only happens by chance. The transit event causes a small drop in the ...
World's fastest and most sensitive astronomical camera
Jun 18, 2009 |
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The next generation of instruments for ground-based telescopes took a leap forward with the development of a new ultra-fast camera that can take 1,500 finely exposed images per second even when observing extremely ...
Odd discovery may help refine theories about how planets form
Jun 17, 2009 |
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An international team of researchers has found a planet around another star whose orbit is steeply tilted from the plane of the star's equator, a finding that contradicts some theories about how solar systems form.
Mass Loss Leaves Close-In Exoplanets Exposed to the Core
Apr 21, 2009 |
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(PhysOrg.com) -- An international team of scientists has found that giant exoplanets orbiting very close to their stars could lose a quarter of their mass during their lifetime. The team found that planets ...
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3 Questions: Sara Seager on searching for Earth-like planets
Nov 23, 2009 |
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(PhysOrg.com) -- MIT planetary scientist Sara Seager has been studying exoplanets — planets circling stars other than the sun — for many years.
32 New Exoplanets Found (w/ Video)
Oct 19, 2009 |
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(PhysOrg.com) -- Today, at an international ESO/CAUP exoplanet conference in Porto, the team who built the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for ESO's 3.6-metre ...
COROT's exoplanet hunt update
May 22, 2008 |
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Two new exoplanets and an unknown celestial object are the latest findings of the COROT mission. These discoveries mean that the mission has now found a total of four new exoplanets.
Researcher hunts for new planets, seeking clues on solar system's origin
Oct 13, 2009 |
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(PhysOrg.com) -- The Cornell assistant professor of astronomy works on instrumentation that searches the night skies for planets outside our solar system, called extrasolar planets.
Exotic life beyond Earth? Looking for life as we don't know it
Space & Earth / Space Exploration
Sep 18, 2009 |
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Scientists at a new interdisciplinary research institute in Austria are working to uncover how life might evolve with "exotic" biochemistry and solvents, such as sulphuric acid instead of water. Their research ...
Universally speaking, Earthlings share a nice neighborhood
Aug 08, 2008 |
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We don't have spacecraft to take us outside our solar system--not yet, at least. Still, astronomers thought they had a pretty good understanding of how our solar system formed and in turn, how others formed. ...
The CoRoT space mission: Early results
Oct 22, 2009 |
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Astronomy & Astrophysics is publishing a special issue this week dedicated to the early results of the CoRoT space mission. The CoRoT (Convection, Rotation & planetary Transits) satellite is a 30 centimeter space ...
A faraway planet intrigues: Exoplanet with extremely tilted orbit raises new interest in stellar astronomy
Nov 12, 2009 |
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(PhysOrg.com) -- Two teams of astronomers have found a planet outside the solar system that might be orbiting backwards compared to its star's rotation, a discovery that could shed light on how unique the ...
Future looks bright for interferometry
Sep 19, 2008 |
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The PRIMA instrument of the ESO Very Large Telescope Interferometer (VLTI) recently saw "first light" at its new home atop Cerro Paranal in Chile. When fully operational, PRIMA will boost the capabilities ...
The Hot Saturn Exoplanet
Oct 02, 2009 |
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(PhysOrg.com) -- Of the roughly 350 known exoplanets (i.e., extrasolar planets), the one orbiting the star HD149026 is unique.
List of search results for exoplanets
