Kepler-7 b

Kepler-7b is one of the first five exoplanets to be confirmed by NASA's Kepler spacecraft, and was confirmed during the first 34 days of Kepler's science operations. It orbits a star slightly hotter and significantly larger than the Sun that is expected to soon reach the end of the main sequence. Kepler-7b is a hot Jupiter that is about half the mass of Jupiter, but is nearly 1.5 times its size; at the time of its discovery, Kepler-7b was the second most diffuse planet known, surpassed only by WASP-17b. It orbits its host star every five days at a distance of approximately . Kepler-7b was announced at a meeting of the American Astronomical Society on January 4, 2010. It is the first extrasolar planet to have a crude map of cloud coverage.

==Characteristics== thumb|left|Profile of planet Kepler–7b by NASA ===Mass, temperature, and orbit=== Kepler-7b is a hot Jupiter, a Jupiter-like exoplanet orbiting close to its star. Its equilibrium temperature, due to its proximity to its star, is hot and is measured at nearly 1540 K. However, of the first five planets discovered by Kepler, it is the second coolest, being surpassed only by Kepler-6b. This is over twelve times hotter than Jupiter. Kepler-7b has a mass of only 0.433 that of Jupiter but due to proximity to its star the planet has expanded to a radius of 1.478 that of Jupiter. Because of this its mean density is only 0.166 g/cm3, about the same as expanded polystyrene. Only WASP-17b (0.49MJ; 1.66RJ) was known to have a lower density at the time of Kepler-7b's discovery. Such low densities are not predicted by current standard theories of planet formation.