Innes' star was discovered in 1920 byRobert T. A. Innes inUnion Observatory,Union of South Africa, who had discerned its largeproper motion and aparallax of 0.337 arcsec.[9] The discovery was published inCircular of the Union Observatory No. 49, hence its discovery name isUO 49,[10] orIn UOC 49.[11] However,UO designations should be used with caution since they are often not unique for each star: the number in the name is the number ofCircular, so all stars published in oneCircular have identical names. So, all other newfound stars, published in the 49thCircular, may be namedUO 49 too.
It is known for the fact that it had once been considered one of the nearest stars to Earth, due to erroneously measuredparallax. The estimated distance was less than 10light-years in the following studies:
InList of stars nearer than 5 parsecs byEjnar Hertzsprung (1922) its parallax is 0.339 arcsec (distance is 2.95 pc or 9.62 ly), and it is the 4th-closest star system afterAlpha Centauri ABC,Barnard's Star andSirius AB;[12]
InA study of the near-by stars byWillem Jacob Luyten andHarlow Shapley (1930) its parallax is 0.337 arcsec (distance is 2.97 pc or 9.68 ly), and it is the 4th-closest star system after Alpha Centauri ABC, Barnard's Star andLalande 21185 (Sirius is further);[13]
InList of stars nearer than five parsecs byPeter van de Kamp (1930) its parallax is 0.34 arcsec (distance is 2.94 pc or 9.59 ly), and it is the 7th-closest star system after Alpha Centauri ABC, Barnard's Star,Wolf 359,Lalande 21185, Sirius AB andBD-12 4523;[14]
InStars within ten parsecs of the Sun byLouise Freeland Jenkins (1937) its parallax is 0.34 arcsec (distance is 2.94 pc or 9.59 ly), and it is the 6th-closest star system after Alpha Centauri, Barnard's Star, Wolf 359, Lalande 21185 and Sirius.[11]
Its actual distance is 12.676 parsecs (41.34 light-years), based on the parallax fromGaia DR3:0.07889±0.00003 arcsec.[2]
In 2014, asub-Neptune-mass planet,Gliese 422 b, of approximately ten Earth-masses, was discovered around this star. It orbits the star every 20 days and lies at a distance of around 0.11astronomical units (AU)—11% of the distance between the Earth and Sun—on the inner edge of the stellar system'shabitable zone, which for this star has been calculated to lie between 0.11 and 0.21 AU.[8]
The discovery of GJ 422 b was confirmed in 2020.[15]
^abcAntoniadis-Karnavas, A.; Sousa, S. G.; Delgado-Mena, E.; Santos, N. C.; Andreasen, D. T. (2024-10-01). "ODUSSEAS: Upgraded version with new reference scale and parameter determinations for 82 planet-host M dwarf stars in SWEET-Cat".Astronomy & Astrophysics.690: A58.arXiv:2408.15808.Bibcode:2024A&A...690A..58A.doi:10.1051/0004-6361/202450722.ISSN0004-6361.
^Worssell, W. M. (1920). "Parallax and Proper Motion of a Faint Star in the Sydney Zone".Circular of the Union Observatory Johannesburg.49: 55.Bibcode:1920CiUO...49...55W.
^Porter, J. G.; Yowell, E. J.; Smith, E. S. (1930). "A catalogue of 1474 stars with proper motion exceeding four-tenths year".Publications of the Cincinnati Observatory.20: 1.Bibcode:1930PCinO..20....1P.
^Hertzsprung, E. (1922). "Remark on the period of VV Orionis".Bulletin of the Astronomical Institutes of the Netherlands.1: 22.Bibcode:1922BAN.....1...22H.
^Luyten, Willem Jacob; Shapley, Harlow (1930). "A study of the near-by stars".Annals of the Astronomical Observatory of Harvard College.85 (5): 73.Bibcode:1930AnHar..85...73L.
^Van De Kamp, P. (1930). "List of stars nearer than five parsecs".Popular Astronomy.38: 17.Bibcode:1930PA.....38...17V.
