Astronomy:HD 222155
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[1] mas/yr Dec.: -117.335[1] mas/yr |
| Parallax (π) | 19.8020 ± 0.0160[1] mas |
| 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 |
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]
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
Based 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
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Boisse, Isabelle; Pepe, Francesco; Perrier, Christian; Queloz, Didier; Bonfils, Xavier; Bouchy, François; Santos, Nuno C.; Arnold, Luc et al. (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, doi:10.1051/0004-6361/201118419, Bibcode: 2012A&A...545A..55B
- ↑ 3.0 3.1 3.2 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, doi:10.3847/1538-3881/aa5df3, Bibcode: 2017AJ....153..136S
- ↑ 4.0 4.1 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, doi:10.1093/mnras/stz3408, Bibcode: 2020MNRAS.492..352K
- ↑ 5.0 5.1 5.2 "HD 222155". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+222155.
- ↑ 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, doi:10.3847/1538-3881/aa8d69, Bibcode: 2017AJ....154..184W
- ↑ 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, doi:10.3847/1538-3881/ab7d3b, Bibcode: 2020AJ....159..194V
- ↑ 9.0 9.1 Philipot, F. et al. (January 2023). "Updated characterization of long-period single companion by combining radial velocity, relative astrometry, and absolute astrometry". Astronomy & Astrophysics 670: A65. doi:10.1051/0004-6361/202245396. Bibcode: 2023A&A...670A..65P.
Coordinates: 
23h 38m 00.3072s, +48° 59′ 47.4865″
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