| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 10 22 43.5923 |
| Declination | +50° 07′ 42.062″ |
| Apparent magnitude (V) | 9.732 |
| Characteristics | |
| Spectral type | G5V |
| B−V color index | 0.86 |
| Astrometry | |
| Radial velocity (Rv) | 12.86(15) km/s |
| Proper motion (μ) | RA: −26.110(14) mas/yr Dec.: 83.806(16) mas/yr |
| Parallax (π) | 12.2731 ± 0.0155 mas |
| Distance | 265.7 ± 0.3 ly (81.5 ± 0.1 pc) |
| Absolute magnitude (MV) | 5.22±0.14 |
| Details | |
| Mass | 0.936+0.028 −0.033 M☉ |
| Radius | 1.062+0.046 −0.013 R☉ |
| Luminosity | 0.77±0.09 L☉ |
| Surface gravity (log g) | 4.357+0.039 −0.005 cgs |
| Temperature | 5,314±50 K |
| Metallicity | 0.30±0.09 dex |
| Rotation | 28.7±0.4 d |
| Rotational velocity (v sin i) | 1.65±0.26 km/s |
| Age | 9.0+1.4 −2.2 Gyr 12.4±2.6 Gyr |
| Other designations | |
| HAT-P-22, Gaia DR2 846946629987527168, HD 233731, TYC 3441-925-1, GSC 03441-00925, 2MASS J10224361+5007420 | |
| Database references | |
| SIMBAD | data |
HD 233731, or HAT-P-22, is a suspected multiple star system in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye, having an apparent visual magnitude of 9.732. This system is located at a distance of 267 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +13 km/s.
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.
