Astronomers have found what they believe is the hottest exoplanet. Called Wasp 12-b, this charcoal black planet with temperatures exceeding 2,200 degrees Celsius (4,000 degrees Fahrenheit) is hotter than some stars, and about half the temperature of our own star - the Sun.
The sizzling planet is also very fast, zipping around its parent star (sun), about once a day. This is quite a contrast to the fastest planet in our Solar System-Mercury, which takes 88 days to orbit around the Sun.
To maintain this orbit pace, Wasp 12-b has to get really close to its Sun - a fact that is interesting to scientists because it pushes the limits on how close a planet can get before being evaporated by the Sun's heat. Scientists believe that there are planets that may even be faster than this one that are just waiting to be discovered.
Wasp-12b, a gaseous planet, is about 1.5 times the mass and almost twice the size of Jupiter. It is extremely far from the Earth, orbiting from a distance of about 870 light years (one light year is the distance light travels in one year). It is one of 50 extrasolar planets that have been discovered by the transit method (see picture), meaning they were found by measuring the dip in brightness of their parent star as the planet passes in front of it and blocks some of its light. Using this method, scientists can not only find the planet, but can also estimate its size, mass, and density, and by measuring how close it gets to its star, they can also determine its temperature. The planet was discovered under the United Kingdom based Super Wasp project, which uses powerful telescopes situated on Spain's Canary Islands and in South Africa to scan the skies.
An extrasolar planet or exoplanet is a planet beyond our Solar System, one that is orbiting around a difference star. The first exoplanet was discovered in the 1990's - since then about 15 new ones have been discovered annually. As of October 2008, a total of 313 exoplanets are known to exist, though a vast majority of them have been detected through indirect methods like the transit method, rather than direct imaging, meaning that we don't have any actual pictures of them. The pictures of Wasp 12-b shown here are all artist renditions of what they believe it would look like.
Sources: LiveScience.com, MSNBC.com