Kapteyn's Star is a class M1 red dwarf star about 13 light years from Earth in the southern constellation of Pictor. With a magnitude of nearly 9 it is visible through binoculars or a telescope.
The star now known as Kapteyn's Star was originally cataloged by the Dutch astronomer, Jacobus Kapteyn, in 1898. While he was reviewing star charts and photographic plates he noted the star's very high proper motion of more than 8 arc seconds per year. Later, the star became referred to as Kapteyn's Star, in honor of its discoverer. At that time, it had the highest proper motion of any star known, dethroning Groombridge 1830. With the discovery of Barnard's Star in 1916, Kapteyn's Star dropped to second place, where it remains. This star came within 2.15 parsecs (7.0 light-years) of the Sun about 10.8 thousand years ago.
Kapteyn's Star is a main sequence star between one quarter and one third the size and mass of the Sun and much cooler at about 3500°K, with some disagreement in the exact measurements between different observers.It is a variable star identified as VZ Pictoris and is of the BY Draconis variable type.
This star is distinctive in a number of other regards: it has a high radial velocity, orbits the Milky Way retrograde, and is the nearest known halo star to the Sun.
Element abundances indicate that Kapteyn's Star may originally have been part of Omega Centauri, a globular cluster that is thought to be the remnant of a dwarf galaxy that merged with the Milky Way.
Kapteyn's Star in space opera:
- Doctor Who? novels by Kate Orman?. Kapteyn's Star is mentioned as home system to several dozen intelligent species who occupy many terrestrial and aquatic ecological niches.
- Frontier: Elite II? and Frontier: First Encounters, computer games. Like Groombridge 1618, Kapteyn's Star is totally uninhabited.
- Has a station in the Alliance Union universe.