About this world
HAT-P-17 b is a gas giant orbiting HAT-P-17, an orange dwarf (type K) 301 light-years from Earth. It is about 1 times the size of Jupiter and holds 0.58 Jupiter masses. It completes an orbit every 10.3 days at 0.089 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.35).
Its equilibrium temperature is about 800 K (527 °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: 6 spectroscopic observations, 1 of them with the James Webb Space Telescope.
It was discovered in 2012 by transit with HATNet. A planet crosses its star and dims it by a tiny, periodic fraction. HAT-P-17 has 2 known planets; the others are HAT-P-17 c.