HD 222155 is astar in the northernconstellation ofAndromeda.[8] 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 anapparent visual magnitude of 7.1. The imaging survey in 2017 did not detect any stellar companions to HD 222155.[9]
This is a G-type star with astellar classification of G0.[4] It has exhausted the hydrogen fuel in its core and begun toevolve towards ared giant; it is currently on thesubgiant branch. It has begun to expand its gaseous envelope, having a radius of 1.8 R☉ with a mass almost the same asthe Sun's[5] The star is relatively depleted of heavy elements, having about 80% of solar abundance, and has weak yet noticeable ultraviolet flare activity.[10][11]
Based on radial velocity data gathered in 2007–2011, the discovery of asuperjovian planet b outside the habitable zone[12] was announced in May 2012.[3] The stellar and planetary parameters were refined in 2016.[13] In 2023, the inclination and true mass of HD 222155 b were measured viaastrometry.[14]
^abBoisse, 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.S2CID119109836.
^abcLlorente De Andrés, F.; de la Reza, R.; Cruz, P.; Cuenda-Muñoz, D.; Alfaro, E. J.; Chavero, C.; Cifuentes, C. (2024). "The evolution of lithium in FGK dwarf stars. Influence of planets and Galactic migration".Astronomy and Astrophysics.684.arXiv:2402.01315.Bibcode:2024A&A...684A..28L.doi:10.1051/0004-6361/202346744.
^Llorente De Andrés, F.; Chavero, C.; de la Reza, R.; Roca-Fàbrega, S.; Cifuentes, C. (2021). "The evolution of lithium in FGK dwarf stars. The lithium-rotation connection and the Li desert".Astronomy and Astrophysics.654.arXiv:2108.05852.Bibcode:2021A&A...654A.137L.doi:10.1051/0004-6361/202141339.
