ホット・ジュピター を発見したのは誰
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/cm<sup>3</sup>, about the same as expanded polystyrene, a substance used to manufacture lightweight, disposable commercial plastic products. Only WASP-17b (0.49"M"; 1.66"R") 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. Kepler-7b orbits its host star every 4.8855 days at a distance of , making it the furthest-orbiting planet of the first five discovered by Kepler. Mercury, in contrast, orbits at a distance of 0.387 AU every 87.97 days. In addition Kepler-7b has an observed orbital inclination of 86.5º, which means that its orbit is almost edge-on as seen from Earth.
Kepler