HAT-P-8b is an extrasolar planet located approximately 720 light years away in the constellation of Pegasus, orbiting the 10th magnitude star GSC 02757-01152.

This is a so-called “hot Jupiter” because this Jupiter-like gas giant planet orbits in a really close torch orbit around the star, making this planet extremely hot (in the order of a thousand kelvins).

The distance from the star is roughly 20 times smaller than that of Earth from the Sun, which places the planet roughly 8 times closer to its star than Mercury is from the Sun.

The “year” on this planet lasts only 3 days, 1 hour, 49 minutes, and 54 seconds, compared with Earth's 365 days, 6 hours, 9 minutes, and 10 seconds in a sidereal year.

[4] The study in 2012, utilizing a Rossiter–McLaughlin effect, have determined the planetary orbit is mildly misaligned with the rotational axis of the star, misalignment equal to -17+9.2−11.5°.