HAT-P-13, also known as GSC 03416-00543, is a G-type main sequence star approximately 811 light-years away in the constellation Ursa Major. In 2009 it was discovered that this star is orbited by two massive planets, the innermost of which transits the star. This was the first known example of an extrasolar transiting planet with an additional planet in the same system. In 2015, a spectroscopic study have revealed a very strong starspot activity of the HAT-P-13 star.