HAT-P-29, also known as Muspelheim since 2019 (as part of the IAU's NameExoWorlds project),[1] is a star about 1040lk=onNaNlk=on away. It is a G-type main-sequence star. The star's age of 2.2 billion years is less than half that of the Sun. HAT-P-29 is slightly enriched in heavy elements, having 35% more iron than the Sun.
A very faint 19th-magnitude stellar companion was detected in 2016 at a projected separation of 3.290″, but Gaia DR2 astrometry suggests that this is an unrelated background object.
In 2011 a transiting hot Jupiter planet, HAT-P-29b, was detected on a mildly eccentric orbit. The planet was named "Surt" by Denmark in 2019.[2] The planetary orbit is likely aligned with the equatorial plane of the star, with a misalignment equal to 26 degrees.
In 2018, a transit-timing variation survey indicated additional planets with masses exceeding approximately half of Earth are absent in the system.