HD 233731
The stellar classification of the primary is G5V, matching an ordinary G-type main-sequence star. The star has a low level of stellar activity with an estimated age of 9 to 12 billion years old. Its metallicity is twice that of the Sun, unusual for its advanced age. HD 233731 has a similar mass and radius as the Sun, and is spinning with a rotation period of 28.7 days. It is radiating 77% of the luminosity of the Sun from its photosphere at an effective temperature of 5314 K.
A faint stellar companion (2MASS J10224397+5007504) with a red hue is located at an angular separation of 9 arcseconds from the primary. In 2015, a spectroscopic stellar companion was reported with a semimajor axis of less than 33 AU. This star has an effective temperature of 4,000+250
−400 K with a mass of 0.63+0.07
−0.17 M☉.
Planetary system
In 2010 a transiting hot Jupiter like planet was detected, designated HAT-P-22b. It has an equilibrium temperature of 1,463±19 K, and planetary atmosphere is cloudy. The measurement of Rossiter-McLaughlin effect in 2018 has allowed to detect what the planetary orbit is well aligned with the equatorial plane of the star, with a misalignment angle equal to 25°±18°.
In 2017, analysis of additional HARPS data showed a long-term trend that suggested the presence of an additional orbiting companion, HAT-P-22c.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.192 −0.013 MJ |
0.04171 −0.00050 |
3.21223328 | 0.016±0.009 | 86.46±0.41° | 1.060±0.048 RJ |
| c (unconfirmed) | ≥3.0 MJ | — | ≥20.8 years | — | — | — |
References
- ^ 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.
- ^ Bakos, G. Á.; et al. (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.
- ^ Mancini, L.; et al. (2018), "The GAPS programme with HARPS-N at TNG XVI. Measurement of the Rossiter-McLaughlin effect of transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60", Astronomy & Astrophysics, A41: 613, arXiv:1802.03859, Bibcode:2018A&A...613A..41M, doi:10.1051/0004-6361/201732234, S2CID 73565379.
- ^ "HD 233731". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2015-12-10.
{{cite web}}: CS1 maint: postscript (link) - ^ Piskorz, Danielle; et al. (2015), "Friends of Hot Jupiters. III. An Infrared Spectroscopic Search for Low-Mass Stellar Companions", The Astrophysical Journal, 814 (2): 148, arXiv:1510.08062, Bibcode:2015ApJ...814..148P, doi:10.1088/0004-637X/814/2/148, S2CID 11525988.
- ^ Turner, Jake D.; et al. (2016), "Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits", Monthly Notices of the Royal Astronomical Society, 459 (1): 789–819, arXiv:1603.02587, Bibcode:2016MNRAS.459..789T, doi:10.1093/mnras/stw574, S2CID 8769245.
- ^ Bonomo, A. S.; et al. (2017), "The GAPS Programme with HARPS-N at TNG. XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets", Astronomy and Astrophysics, 602, A107, arXiv:1704.00373, Bibcode:2017A&A...602A.107B, doi:10.1051/0004-6361/201629882.
