This system, also known as Lalande 21258, was announced in 1860 as a high apparent proper motion star byFriedrich Wilhelm Argelander as a result of work on theBonner Durchmusterung (BD).[17]Adalbert Krueger, an assistant to the BD project, was tasked with measuring its parallax. In Krueger's paper reporting the result, he dubbed it Argelander's Third Star.[18]
The primary star was monitored forradial velocity (RV) variations caused by aJupiter-mass companion in a short-period orbit. It displayed no significant excess of RV variation that could be attributed to a planet.[19] A search of the system using near-infrared speckle interferometry also failed to detect a companion orbiting at distances of 1–10 AU.[20] Nor has abrown dwarf been detected orbiting within this system.[21]
The primary has 0.387 times themass of the Sun, 0.398 times theSun's radius and 2.23% of theSun's luminosity.[10] It is spinning at arotation velocity at theequator of less than 3 km/s.[12] The secondary is smaller and fainter, at 9.52% of the Sun's mass, 12.62% of the Sun's radius[13] and luminosity only 0.09% solar.[14] It is spinning at a rotation velocity of7.7±1.7 km/s.[12] Gliese 412 A has a temperature of 3,639K,[10] while Gliese 412 B has 2,863 K.[13]
Thespace velocity components of this system are U = 141, V = –7 and W = 7. They are members of the halo population of theMilky Way galaxy.[12]
The secondary is aflare star that is referred to as WX Ursae Majoris. It is characterized as aUV Ceti-type variable star that displays infrequent increases in luminosity. This star was observed to flare as early as 1939 by the Dutch astronomerAdriaan van Maanen.[23]
Component B (WX Ursae Majoris) has been identified as anX-ray source, while no significant X-ray emission was detected from component A.[24] This system had not been studied in X-rays prior toROSAT.[24]
^abcdefghSchweitzer, Andreas; Passegger, V. M.; Cifuentes, C.; Bejar, V. J. S.; Cortes-Contreras, M.; Caballero, J. A.; del Burgo, C.; Czesla, S.; Kuerster, M.; Montes, D.; Osorio, M. R. Zapatero; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J. (May 2019). "The CARMENES search for exoplanets around M dwarfs: Different roads to radii and masses of the target stars".Astronomy & Astrophysics.625: A68.arXiv:1904.03231.Bibcode:2019A&A...625A..68S.doi:10.1051/0004-6361/201834965.ISSN0004-6361.
^abcdeDelfosse, Xavier; Forveille, Thierry; Perrier, Christian; Mayor, Michel (March 1998). "Rotation and chromospheric activity in field M dwarfs".Astronomy and Astrophysics.331:581–595.Bibcode:1998A&A...331..581D.
^Leinert, C.; et al. (September 1997). "A search for companions to nearby southern M dwarfs with near-infrared speckle interferometry".Astronomy and Astrophysics.325:159–166.Bibcode:1997A&A...325..159L.
^Reid, I. Neill; Gizis, John E. (June 1997). "Low-Mass Binaries and the Stellar Luminosity Function".Astronomical Journal.113:2246–2269.Bibcode:1997AJ....113.2246R.doi:10.1086/118436.
^Joy, Alfred H. (June 1967). "Stellar Flares".Astronomical Society of the Pacific Leaflets.10 (456):41–48.Bibcode:1967ASPL...10...41J.
