HD 222155 is a star in the northern constellation of Andromeda.[5] It is a yellow star that can be viewed with binoculars or a small telescope, but is too faint to be seen with the naked eye at an apparent visual magnitude of 7.1. The imaging survey in 2017 did not detect any stellar companions to HD 222155.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 38m 00.30719s[1] |
| Declination | +48° 59′ 47.4874″[1] |
| Apparent magnitude (V) | 7.1[2] |
| Characteristics | |
| Evolutionary stage | main sequence star |
| Spectral type | G0V |
| B−V color index | 0.64 |
| Astrometry | |
| Radial velocity (Rv) | −44.00±0.12[1] km/s |
| Proper motion (μ) | RA: 195.306 mas/yr[1] Dec.: -117.335 mas/yr[1] |
| Parallax (π) | 19.8020 ± 0.0160 mas[1] |
| Distance | 164.7 ± 0.1 ly (50.50 ± 0.04 pc) |
| Details[2][3][4] | |
| Mass | 1.21±0.10 M☉ |
| Radius | 1.85±0.04 R☉ |
| Luminosity | 3.2 L☉ |
| Surface gravity (log g) | 4.10±0.13 cgs |
| Temperature | 5720±44 K |
| Metallicity [Fe/H] | -0.11±0.05 dex |
| Rotational velocity (v sin i) | 3.2±1.0 km/s |
| Age | 8.2±0.7 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an old main sequence star with a stellar classification of G0V;[5] a star that is nearing an exhaustion of its hydrogen fuel. It is already beginning to expand its gaseous envelope,[2] having radius of 1.85R☉.[3] The star is relatively depleted of heavy elements, having about 80% of solar abundance, and has weak yet noticeable ultraviolet flare activity.[7][8]
Planetary system
editBased on radial velocity data gathered in 2007-2011, the discovery of a superjovian planet b outside the habitable zone[4] was announced in May 2012.[2] The stellar and planetary parameters were refined in 2016.[3] In 2023, the inclination and true mass of HD 222155 b were measured via astrometry.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.1+0.3 −0.2 MJ |
4.7±0.1 | 3470+102 −106 |
0.34±0.09 | 66+14 −11 or 115+13 −16° |
— |
References
edit- ^ a b c d e 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.
- ^ a b c d Boisse, Isabelle; Pepe, Francesco; Perrier, Christian; Queloz, Didier; Bonfils, Xavier; Bouchy, François; Santos, Nuno C.; Arnold, Luc; Beuzit, Jean-Luc; Dìaz, Rodrigo F.; Delfosse, Xavier; Eggenberger, Anne; Ehrenreich, David; Forveille, Thierry; Hébrard, Guillaume; Lagrange, Anne-Marie; Lovis, Christophe; Mayor, Michel; Moutou, Claire; Naef, Dominique; Santerne, Alexandre; Ségransan, Damien; Sivan, Jean-Pierre; Udry, Stéphane (2012), "The SOPHIE search for northern extrasolar planets V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars", Astronomy and Astrophysics, 545: A55, arXiv:1205.5835, Bibcode:2012A&A...545A..55B, doi:10.1051/0004-6361/201118419, S2CID 119109836
- ^ a b c Stassun, Keivan G.; Collins, Karen A.; Gaudi, B. Scott (2016), "Accurate empirical radii and masses of planets and their host stars with Gaia parallaxes", The Astronomical Journal, 153 (3): 136, arXiv:1609.04389, Bibcode:2017AJ....153..136S, doi:10.3847/1538-3881/aa5df3, S2CID 119219062
- ^ a b Kokaia, Giorgi; Davies, Melvyn B.; Mustill, Alexander J. (2020), "Resilient habitability of nearby exoplanet systems", Monthly Notices of the Royal Astronomical Society, 492 (1): 352–368, arXiv:1910.07573, Bibcode:2020MNRAS.492..352K, doi:10.1093/mnras/stz3408, S2CID 204743669
- ^ a b c "HD 222155". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 17 September 2020.
- ^ Wittrock, Justin M.; Kane, Stephen R.; Horch, Elliott P.; Howell, Steve B.; Ciardi, David R.; Everett, Mark E. (2017), "Exclusion of Stellar Companions to Exoplanet Host Stars", The Astronomical Journal, 154 (5): 184, arXiv:1709.05315v1, Bibcode:2017AJ....154..184W, doi:10.3847/1538-3881/aa8d69, S2CID 55789971
- ^ Evgenya L. Shkolnik, "AN ULTRAVIOLET INVESTIGATION OF ACTIVITY ON EXOPLANET HOST STARS", 2013
- ^ Viswanath, Gayathri; Narang, Mayank; Manoj, P.; Mathew, Blesson; Kartha, Sreeja S. (2020), "A statistical search for Star-Planet Interaction in the UltraViolet using GALEX", The Astronomical Journal, 159 (5): 194, arXiv:2003.03349v1, Bibcode:2020AJ....159..194V, doi:10.3847/1538-3881/ab7d3b, S2CID 212628609
- ^ a b Philipot, F.; Lagrange, A.-M.; et al. (January 2023). "Updated characterization of long-period single companion by combining radial velocity, relative astrometry, and absolute astrometry". Astronomy & Astrophysics. 670: A65. arXiv:2301.01263. Bibcode:2023A&A...670A..65P. doi:10.1051/0004-6361/202245396. S2CID 255393653.