[25][22] Data published in 2017 from the HIRES system at the Keck Observatory on Mauna Kea supported the existence of a close-in planet with an orbital period of just 9.8693±0.0016 days, being at least 3.8 ME.

[27] The proposed planet on 12-day orbit was confirmed by CARMENES [ja] (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) project in 2020.

[8] Dutch astronomer Peter van de Kamp wrote in 1945 that Lalande 21185 possessed an "unseen companion" of 0.06 M☉ (about 60 MJ).

[30] In 1951 van de Kamp and his student Sarah Lippincott claimed the astrometric detection of a planetary system using photographic plates taken with the 24-inch (610 mm) refractor telescope at Swarthmore College's Sproul Observatory.

[31] In the summer of 1960, Sarah Lippincott altered the 1951 claim, to a planet of 0.01 M☉ (that is, 10 MJ), an 8-year orbital period, eccentricity of 0.3, a semi-major axis[nb 3] of 0.083 AU.

[33] Photographic plates from this observatory, taken at the same time, were used by Van de Kamp for his erroneous claim of a planetary system for Barnard's Star.

[35] In 1996 the same Gatewood prominently announced at an AAS meeting[36] and to the popular press[37] the discovery of multiple planets in this system, detected by astrometry.

The initial report was based on a very delicate analysis of the star's position over the years, which suggested reflex orbital motion due to one or more companions.

Though, a paper by Gatewood published only a few years earlier[38] and later searches by others, using coronagraphs and multifilter techniques to reduce the scattered-light problems from the star, did not positively identify any such companions,[39] and so his claim remains unconfirmed and is now in doubt.

Before the 1980s, finding the radial velocity of red dwarfs was neither very accurate nor consistent, and so due to its apparent brightness and because it does not have a companion, this star, along with eleven other similar red dwarf stars, were chosen to have their radial velocity measured, to unprecedented high accuracy, by planet hunter Geoff Marcy.