Kapteyn’s Star

modern name for HD 33793 = GJ 191, a high proper motion M1 subdwarf at d=4pc (V=8.8). The star was unusual – very blue but M1 type, high pm and very high radial velocity (242 km/s). Two recent exoplanet candidates reported (Anglada-Escude+2014) but both have been rebutted (Bortles+2021).

Etymology and History

Kapteyn's original note of the discovery.

This was 2nd highest proper motion star in 1927 according to Luyten and still is! (8.7”/yr). It was pointed out as highest proper motion (at time) by Kapteyn (1897) “Stern mit grösster bislang bekannter Eigenbewegung” (“Star with largest self-motion known to date”)

Luyten giving the name "Kapteyn" to a star

The name appears to be from Luyten (1927) “Note on the Magnitude and Spectrum of Kapteyn's Star”.

• "Kapteyn" in Allen (1963; Astrophysical Quantities),
• "Kapteyn's Star" in Rhoads (1971),
• Burnham (1978),
• Fernandez+(1983),
• Sinnott & Perryman Millenium Atlas (1997),
• Cox (2000; Astrophysical Quantities),
• Kaler (2006).
• NASA ADS shows “Kapteyn’s star” listed in 44 abstracts
• Name is already in SIMBAD. Wikipedia

IAU Star Name

WGSN discussed the name in 2022 but decided (for the time being) not to name stars after people.