HAT-P-29, also known as

Muspelheim In Norse cosmology, Muspelheim (), also called Muspell (), is a realm of fire. The etymology of "Muspelheim" is uncertain, but may come from ''Mund-spilli'', "world-destroyers", "wreck of the world". Narrative Muspelheim was described as a ho ...

since 2019 (as part of the

IAU The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) were various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, notably exoplanets. The accepted names would later be cons ...

project), is a star about away. It is a

G-type main-sequence star A G-type main-sequence star (spectral type: G-V), also often, and imprecisely, called a yellow dwarf, or G star, is a main sequence, main-sequence star (luminosity class V) of stellar classification, spectral type G. Such a star has about 0.9 to ...

. The star's age of 2.2 billion years is less than half that of the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

. 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.

Planetary system

In 2011 a transiting

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter (i.e. Jupiter analogue, Jupiter analogues) but that have very short orbital periods (). The close proximity to t ...

planet, HAT-P-29b, was detected on a mildly eccentric orbit. The planet was named " Surt" by

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

in 2019. 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 Transit-timing variation is a method for detecting exoplanets by observing variations in the timing of a transit. This provides an extremely sensitive method capable of detecting additional planets in the system with masses potentially as small a ...

survey indicated additional planets with masses exceeding approximately half of Earth are absent in the system.

References

Perseus (constellation) G-type main-sequence stars Binary stars Planetary systems with one confirmed planet Planetary transit variables J02123147+5146435

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