About this world
HAT-P-2 b is a gas giant orbiting HAT-P-2, a yellow-white F-type star (type F8) 417 light-years from Earth. It is about 0.95 times the size of Jupiter and holds 9 Jupiter masses. It completes an orbit every 5.63 days at 0.068 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.52).
Its equilibrium temperature is about 1,540 K (1,267 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium. Its atmosphere has already been studied: 23 spectroscopic observations.
It was discovered in 2007 by transit with HATNet. A planet crosses its star and dims it by a tiny, periodic fraction. HAT-P-2 has 2 known planets; the others are HAT-P-2 c.