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One of the things that makes it special is that it has a climate that is similar to Earth's climate.
The temperature on the planet ranges from between 314 degrees Fahrenheit (157 degrees Celsius, or 430 kelvin) and -10 degrees Fahrenheit (-23 degrees Celsius, or 250 kelvin).
And, the exoplanet has a size similar to the planet Jupiter (about 84% the mass of Jupiter, the largest planet in our Solar System).
Further, it orbits its parent star at a distance similar to the planet Mercury (about 0.36 astronomical unit [AU] or about 53.8 million kilometers, 33.5 million miles), the closest planet to the Sun in our Solar System.
The exoplanet was discovered, on March 17, 2010, by the space probe COROT (short for COnvection ROtation and planetary Transits). Further information on the discovery is found in the University of Oxford article "Cool Jupiter exoplanet found."
COROT was launched by the French Space Agency (CNES), the European Space Agency (ESA), the German Aerospace Center (DLR), and other international partners.
Page two continues with more about the Corot-9b exoplanet.
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So far about 400 exoplanets have been found orbiting stars other than the Sun. Corot-9b stands alone because it is considered to be able to provide valuable scientific discoveries in the study of planets outside of our Solar System.
Corot-9b is located about 1,500 light years from our Solar System, in the constellation Serpens. It orbits its parent star once every 95 days at a distance of about 0.36 astronomical unit (AU).
The research about Corot-9b was published on March 18, 2010 in the journal Nature. Its title 'A transiting giant planet with a temperature between 250'‰K and 430'‰K' (Nature 464, 384-387 (18 March 2010), doi:10.1038/nature08856) was authored by an international array of scientists.
The scientists state in their Nature article 'Here we report transit observations of CoRoT-9b, which orbits with a period of 95.274'‰days on a low eccentricity of 0.11'‰±'‰0.04 around a solar-like star. Its periastron distance of 0.36 astronomical units is by far the largest of all transiting planets, yielding a 'temperate' photospheric temperature estimated to be between 250 and 430'‰K.'
According to Claire Montou, from the European Southern Observatory and one of the astronomers that made the discovery of Corot-9b, 'This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth.... It is bound to become a Rosetta stone in exoplanet research.' [IO9.com: 'Is Corot-9b Cool Enough To Be Earth-2?"]
Page three talks about the uniqueness of Corot-9b.
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These discovering astronomers state within their paper, 'Indeed, the planet is found to be well described by standard evolution models with an inferred interior composition consistent with that of Jupiter and Saturn.'
What really makes Corot-9b special, along with its composition and temperature is the fact that we are able to study it as it passes in front of its parent star. It is one of only less than 20% discovered exoplanets that transit their parent star.
They further state in their Nature paper, 'Of the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres.'
The research of Corot-9b centers around the time that it crosses the face of its parent star (what is called its 'transit'). During this eight-hour period, which happens once every 95 days, astronomers have a perfect time to discover all there is to know about the planet.
Corot-9b is a gaseous planet that has moderate temperatures when compared to temperatures on our planet Earth. The temperature on Corot-9b varies depending on the amount of cloud cover surrounding its surface. More cloud cover reflects more heat from its star, and less cloud cover allow more heat to impinge on its surface.
Page four concludes with the hope of finding a lot out about this very special planet out there about 1,500 light years away.
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U.S. astrophysicist Alan P. Boss, from the Carnegie Institution for Science in Washington, D.C., states, 'This discovery adds weight to the fact that we know that planets often orbit in or close to the habitable zone, so we should not be surprised when the Kepler or COROT satellites or some ground-based search makes the claim for the first habitable Earth or super-Earth.' [Science News (3.17.2010): 'This exoplanet is so cool']
Dr. Boss says the discovery of Corot-9b, along with its physical characteristics and its similarity with planets in our Solar System, adds hope that we can learn much about this exoplanet.
Boss states because, '... where there is gold dust there might be a gold mine.' [Science News]
Learn more about Corot-9b at the March 18, 2010 DLR article "CoRoT-9b, a temerate exoplanet."
