HAT-P-20
HAT-P-20 is a K-type main-sequence star about 232 light-years away. The star has a strong starspot activity,[2] and its equatorial plane is misaligned by 36+10
−12° with the planetary orbit.[3] 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.[4]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Gemini |
| Right ascension | 07h 27m 39.9487s[1] |
| Declination | +24° 20′ 11.5183″[1] |
| Apparent magnitude (V) | 11.35[1] |
| Characteristics | |
| Spectral type | K3V |
| Astrometry | |
| Radial velocity (Rv) | -18.559 km/s |
| Proper motion (μ) | RA: -4.985 mas/yr Dec.: -96.235 mas/yr |
| Parallax (π) | 14.0483 ± 0.0391[1] mas |
| Distance | 232.2 ± 0.6 ly (71.2 ± 0.2 pc) |
| Details[2][3] | |
| Mass | 0.798±0.018 M☉ |
| Radius | 0.744±0.011 R☉ |
| Surface gravity (log g) | 4.52±0.09 cgs |
| Temperature | 4595±45 K |
| Metallicity | 0.22±0.09 |
| Rotation | 14.66±0.03 d |
| Rotational velocity (v sin i) | 2.0±0.5 km/s |
| Age | 0.8 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Planetary system
In 2010 a transiting hot super-Jovian planet was detected.[5] Its equilibrium temperature is 996±19 K.
Size comparison of HAT-P-20 b and Jupiter
| 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
- HAT-P-20 -- High proper-motion Star
- Leilei Sun, Shenghong Gu, Xiaobin Wang at al., "REFINED SYSTEM PARAMETERS AND TTV STUDY OF TRANSITING EXOPLANETARY SYSTEM HAT-P-20", 2017
- 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, doi:10.1051/0004-6361/201629720, S2CID 119341241
- 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, doi:10.1051/0004-6361/201425243, S2CID 55139248
- 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, doi:10.1088/0004-637X/742/2/116, S2CID 119182075
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