HAT-P-20 is a K-type main-sequence star about 233 light-years away. The star has a strong starspot activity,[3] and its equatorial plane is misaligned by 36+10
−12
° with the planetary orbit.[4] Although star with a giant planet on close orbit is expected to be spun-up by tidal forces, only weak indications of tidal spin-up were detected.[5]

HAT-P-20
Observation data
Epoch J2000      Equinox J2000
Constellation Gemini
Right ascension 07h 27m 39.9489s[1]
Declination +24° 20′ 11.516″[1]
Apparent magnitude (V) 11.35[2]
Characteristics
Spectral type K3V
Astrometry
Radial velocity (Rv)-18.559 km/s
Proper motion (μ) RA: −5.104(18) mas/yr[1]
Dec.: −96.090(16) mas/yr[1]
Parallax (π)14.0065 ± 0.0176 mas[1]
Distance232.9 ± 0.3 ly
(71.40 ± 0.09 pc)
Details[3][4]
Mass0.798±0.018 M
Radius0.744±0.011 R
Surface gravity (log g)4.52±0.09 cgs
Temperature4595±45 K
Metallicity0.22±0.09
Rotation14.66±0.03 d
Rotational velocity (v sin i)2.0±0.5 km/s
Age0.8 Gyr
Other designations
Gaia DR2 869913435026514688, 2MASS J07273995+2420118[2]
Database references
SIMBADdata

Planetary system

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In 2010 a transiting hot super-Jovian planet was detected.[6] Its equilibrium temperature is 996±19 K.

 
Size comparison of HAT-P-20 b and Jupiter
The HAT-P-20 planetary system[6][3][4]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 7.59±0.12 MJ 0.03671±0.00027 2.8753172±0.0000003 0.0172±0.0016 86.3±0.1° 0.952±0.017 RJ

References

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  1. ^ a b c d 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 HAT-P-20 -- High proper-motion Star
  3. ^ a b c Leilei Sun, Shenghong Gu, Xiaobin Wang at al., "REFINED SYSTEM PARAMETERS AND TTV STUDY OF TRANSITING EXOPLANETARY SYSTEM HAT-P-20", 2017
  4. ^ a b c Esposito, M.; Covino, E.; Desidera, S.; Mancini, L.; Nascimbeni, V.; Zanmar Sanchez, R.; Biazzo, K.; Lanza, A. F.; Leto, G.; Southworth, J.; Bonomo, A. S.; Suárez Mascareño, A.; Boccato, C.; Cosentino, R.; Claudi, R. U.; Gratton, R.; Maggio, A.; Micela, G.; Molinari, E.; Pagano, I.; Piotto, G.; Poretti, E.; Smareglia, R.; Sozzetti, A.; Affer, L.; Anderson, D. R.; Andreuzzi, G.; Benatti, S.; Bignamini, A.; et al. (2017), "The GAPS Programme with HARPS-N at TNG. XIII. The orbital obliquity of three close-in massive planets hosted by dwarf K-type stars: WASP-43, HAT-P-20 and Qatar-2.", Astronomy & Astrophysics, 601: A53, arXiv:1702.03136, Bibcode:2017A&A...601A..53E, doi:10.1051/0004-6361/201629720, S2CID 119341241
  5. ^ Salz, M.; Schneider, P. C.; Czesla, S.; Schmitt, J. H. M. M. (2015), "High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood", Astronomy & Astrophysics, 576: A42, arXiv:1502.00576, Bibcode:2015A&A...576A..42S, doi:10.1051/0004-6361/201425243, S2CID 55139248
  6. ^ a b Bakos, G. Á.; Hartman, J.; Torres, G.; Latham, D. W.; Kovács, Géza; Noyes, R. W.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.; Kipping, D.; Esquerdo, G. A.; Shporer, A.; Béky, B.; Buchhave, L. A.; Perumpilly, G.; Everett, M.; Sasselov, D. D.; Stefanik, R. P.; Lázár, J.; Papp, I.; Sári, P. (2010), "HAT-P-20b–HAT-P-23b: FOUR MASSIVE TRANSITING EXTRASOLAR PLANETS", The Astrophysical Journal, 742 (2): 116, arXiv:1008.3388, Bibcode:2011ApJ...742..116B, doi:10.1088/0004-637X/742/2/116, S2CID 119182075