HAT-P-29, also known as Muspelheim since 2019 (as part of the IAU's NameExoWorlds project),[6] is a star about 1,040 light-years (320 parsecs) away. It is a G-type main-sequence star. The star's age of 2.2±1.0 billion years is less than half that of the Sun.[4] HAT-P-29 is slightly enriched in heavy elements, having 35% more iron than the Sun.

HAT-P-29 / Muspelheim
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 02h 12m 31.47875s[1]
Declination +51° 46′ 43.5637″[1]
Apparent magnitude (V) 11.83
Characteristics
Evolutionary stage main-sequence star
Spectral type G
Astrometry
Radial velocity (Rv)−21.91±0.69[1] km/s
Proper motion (μ) RA: -9.972 mas/yr[1]
Dec.: 1.790 mas/yr[1]
Parallax (π)3.1358 ± 0.0201 mas[1]
Distance1,040 ± 7 ly
(319 ± 2 pc)
Orbit[2]
PrimaryHAT-P-29
CompanionHAT-P-29 B
Semi-major axis (a)3.290±0.002"
(1041 AU)
Details[3]
Mass1.198+0.065
−0.063
 M
Radius1.229+0.080
−0.073
 R
Luminosity1.89+0.3
−0.25
 L
Surface gravity (log g)4.337+0.045
−0.045
 cgs
Temperature6112±88 K
Metallicity [Fe/H]0.128+0.079
−0.080
 dex
Age2.2±1.0[4] Gyr
Other designations
Muspelheim, Gaia DR2 359058441314838528, TYC 3293-1539-1, GSC 03293-01539, 2MASS J02123147+5146435[5]
Database references
SIMBADdata

A very faint 19th-magnitude stellar companion was detected in 2016 at a projected separation of 3.290±0.002″,[2] but Gaia DR2 astrometry suggests that this is an unrelated background object.[7]

Planetary system

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In 2011 a transiting hot Jupiter planet, HAT-P-29b, was detected on a mildly eccentric orbit.[4] The planet was named "Surt" by Denmark in 2019.[8] The planetary orbit is likely aligned with the equatorial plane of the star, with a misalignment equal to 26±16 degrees.[9]

In 2018, a transit-timing variation survey indicated additional planets with masses exceeding approximately half of Earth are absent in the system.[3]

The HAT-P-29 planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b (Surt) 0.767+0.046
−0.045
 MJ
0.0665±0.0012 5.723376±0.000021 0.073+0.029
−0.028
88.06+0.78
−0.59
°
1.055+0.079
−0.072
 RJ

References

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  1. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Bryan, Marta; Crepp, Justin R.; Batygin, Konstantin; Crossfield, Ian; Hansen, Brad; Howard, Andrew W.; Johnson, John A.; Mawet, Dimitri; Morton, Timothy D.; Muirhead, Philip S.; Wang, Ji (2016), "FRIENDS OF HOT JUPITERS. IV. STELLAR COMPANIONS BEYOND 50 au MIGHT FACILITATE GIANT PLANET FORMATION, BUT MOST ARE UNLIKELY TO CAUSE KOZAI–LIDOV MIGRATION", The Astrophysical Journal, 827 (1): 8, arXiv:1606.07102, Bibcode:2016ApJ...827....8N, doi:10.3847/0004-637X/827/1/8, S2CID 41083068
  3. ^ a b c Wang, Songhu; Wang, Xian-Yu; Wang, Yong-Hao; Liu, Hui-Gen; Hinse, Tobias C.; Eastman, Jason; Bayliss, Daniel; Hori, Yasunori; Hu, Shao-Ming; Li, Kai; Liu, Jinzhong; Narita, Norio; Peng, Xiyan; Wittenmyer, R. A.; Wu, Zhen-Yu; Zhang, Hui; Zhang, Xiaojia; Zhao, Haibin; Zhou, Ji-Lin; Zhou, George; Zhou, Xu; Laughlin, Gregory (2018), "Transiting Exoplanet Monitoring Project (TEMP). I. Refined System Parameters and Transit Timing Variations of HAT-P-29b", The Astronomical Journal, 156 (4): 181, arXiv:1807.10107, Bibcode:2018AJ....156..181W, doi:10.3847/1538-3881/aadcfc, S2CID 119415237
  4. ^ a b c Buchhave, L. A.; Bakos, G. Á.; Hartman, J. D.; Torres, G.; Latham, D. W.; Andersen, J.; Kovács, G.; Noyes, R. W.; Shporer, A.; Esquerdo, G. A.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.; Béky, B.; Sasselov, D. D.; Fűrész, G.; Quinn, S. N.; Stefanik, R. P.; Szklenár, T.; Berlind, P.; Calkins, M. L.; Lázár, J.; Papp, I.; Sári, P. (2011), "HAT-P-28b AND HAT-P-29b: TWO SUB-JUPITER MASS TRANSITING PLANETS", The Astrophysical Journal, 733 (2): 116, arXiv:1103.1813, Bibcode:2011ApJ...733..116B, doi:10.1088/0004-637X/733/2/116, S2CID 119293967
  5. ^ "HAT-P-29". SIMBAD. Centre de données astronomiques de Strasbourg.
  6. ^ IAU100 NameExoWorlds APPROVED NAMES
  7. ^ Mugrauer, M.; et al. (2019). "Search for stellar companions of exoplanet host stars by exploring the second ESA-Gaia data release". Monthly Notices of the Royal Astronomical Society. 490 (4): 5088. Bibcode:2019MNRAS.490.5088M. doi:10.1093/mnras/stz2673.
  8. ^ Denmark names new planet after Norse fire giant Surt
  9. ^ Mancini, L.; et al. (2022), "The GAPS Programme at TNG", Astronomy & Astrophysics, 664: A162, arXiv:2205.10549, doi:10.1051/0004-6361/202243742, S2CID 248986121