HD 233731
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 10h 22m 43.5924s[1] |
| Declination | +50° 07′ 42.0635″[1] |
| Apparent magnitude (V) | 9.76[1] |
| Characteristics | |
| Spectral type | G5V |
| Astrometry | |
| Radial velocity (Rv) | 12.63 km/s |
| Proper motion (μ) | RA: -26.182 mas/yr Dec.: 83.727 mas/yr |
| Parallax (π) | 12.2014 ± 0.0371 mas[1] |
| Distance | 267.3 ± 0.8 ly (82.0 ± 0.2 pc) |
| Details[2] | |
| Mass | 0.936+0.028 −0.033 M☉ |
| Radius | 1.062+0.046 −0.013 R☉ |
| Surface gravity (log g) | 4.357+0.039 −0.005 cgs |
| Temperature | 5314±50 K |
| Metallicity | 0.30±0.09 |
| Rotation | 28.7±0.4d |
| Rotational velocity (v sin i) | 1.65±0.26 km/s |
| Age | 9.0+1.4 −2.2 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | 233731 data |
HD 233731 is a G-type main-sequence star about 267 light-years away. It has a suspected stellar companions and hosts one known planet, HAT-P-22b.
Characteristics
HD 233731 is a main sequence G-type star. Its age is estimated at 9.0 billion years (twice older than the Sun). Its metallicity is twice that of the the Sun, unusual for its advanced age. The HD 233731 have a low stellar activity[2]. One wide-orbit red dwarf stellar companion with the temperature 4000+250
−400 K and mass 0.63+0.07
−0.17M☉ is suspected, but was not directly imaged as in 2015.[3]
Planetary system
In 2010 a transiting hot Jupiter like planet was detected.[4] It has an equilibrium temperature of 1463±19 K, and planetary atmosphere is cloudy.[5] 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, misalignment angle equal to 25±18°.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.192+0.073 −0.013 MJ |
0.04171+0.00042 −0.00050 |
3.21223328 | 0.016±0.009 | 86.46±0.41° | 1.060±0.048 RJ |
References
- ^ a b c d e HD 233731 -- High proper-motion Star
- ^ a b c d 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, 2018, arXiv:1802.03859
- ^ FRIENDS OF HOT JUPITERS III:AN INFRARED SPECTROSCOPIC SEARCH FOR LOW-MASS STELLAR COMPANIONS, 2015, arXiv:1510.08062
- ^ a b HAT-P-20b--HAT-P-23b: Four Massive Transiting Extrasolar Planets, 2010, arXiv:1008.3388
- ^ Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits, 2016, arXiv:1603.02587
 | This main-sequence-star-related article is a stub. You can help Wikipedia by expanding it. |
 | This extrasolar-planet-related article is a stub. You can help Wikipedia by expanding it. |