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'''Kapteyn's Star''' is one of the closest stars to our [[Solar System]].  The star is noted for its unusual features compared to other local stars, such as its retrograde galactic orbital path, extreme age, and origins outside the galactic plane.  The star was first discovered by  Jacobus Cornelius Kapteyn (1851-1922) and Robert Thorburn Ayton Innes in 1897,<ref name="sol">http://www.solstation.com/stars/kapteyns.htm</ref> and was found to have the greatest proper motion of any star until the discovery of [[Barnard's Star]].

'''Kapteyn's Star''' is one of the closest stars to our [[Solar System]].  The star is noted for its unusual features compared to other local stars, such as its retrograde galactic orbital path, extreme age, and origins outside the galactic plane.  The star was first discovered by  Jacobus Cornelius Kapteyn (1851-1922) and Robert Thorburn Ayton Innes in 1897,<ref name="sol">http://www.solstation.com/stars/kapteyns.htm</ref> and was found to have the greatest proper motion of any star until the discovery of [[Barnard's Star]].

Kapteyn's Star itself is classified as a M0-1.5V(dwarf) or VI(subdwarf) halo star<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1997AJ....113..806G</ref>, meaning its origins are from the [[Milky Way|Milky Way's]] [[galactic halo]], a spherical region around the [[galaxy]] containing very old, [[Metallicity|metal-poor]] stars.  Because the star is a dim M class dwarf with only 4/1000th of the sun's brightness, it has an apparent magnitude of 8.85, rendering it invisible to the unaided eye.  This is despite being located only 12.77 years away, making it the 25th closest star. Kapteyn's Star has only 10.5 percent of the Metallicity of Sol, 29 to 39.3 percent of Sol's mass<ref>http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2004MNRAS.350..575W&db_key=AST&high=41dd40b72e13373</ref>, and less than third (29 to 32 percent) of its diameter<ref name="sol">http://www.solstation.com/stars/kapteyns.htm</ref>.  It is also a [[variable star]], and thus is also known by its variable star designation of ''VZ Pictoris''.

Kapteyn's Star itself is classified as a M0-1.5V(dwarf) or VI(subdwarf) halo star<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1997AJ....113..806G</ref>.  Because the star is a dim M class dwarf with only 4/1000th of the sun's brightness, it has an apparent magnitude of 8.85, rendering it invisible to the unaided eye.  This is despite being located only 12.77 years away, making it the 25th closest star. Kapteyn's Star has only 10.5 percent of the Metallicity of Sol, 29 to 39.3 percent of Sol's mass<ref>http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2004MNRAS.350..575W&db_key=AST&high=41dd40b72e13373</ref>, and less than third (29 to 32 percent) of its diameter<ref name="sol">http://www.solstation.com/stars/kapteyns.htm</ref>.  It is also a [[variable star]], and thus is also known by its variable star designation of ''VZ Pictoris''.

Because Kapteyn's Star is so metal-poor (lacking in elements heavier then [[hydrogen]] and [[helium]]), it appears more bluish and dimmer then the typical younger, main sequence M-class dwarf<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1976ApJ...205..186W</ref>.  Due of the lack of metals, it is generally accepted the star was born in an earlier age and/or region such as the galatic halo where few [[supernova]] have released their metals into the surrounding region (supernova being the general source of all elements above helium on the [[periodic table]]).

Because Kapteyn's Star is so metal-poor (lacking in elements heavier then [[hydrogen]] and [[helium]]), it appears more bluish and dimmer then the typical younger, main sequence M-class dwarf<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1976ApJ...205..186W</ref>.   

Very few such halo stars are located near our solar system, with such stars accounting for only 0.1 to 0.2 percent of all stars that are near the sun. Kapteyn's Star is believed to be the closest of these.  The star is a member of a local cluster of halo stars that is very thinly spread out over a distance of some 6,500 to 9,800 light-years stretching towards the galactic halo<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1996AJ....112.2661E</ref>.  Kapteyn's Star is unusual because most such stars lie far above or below the galactic plane.  Like other halo stars, Kapteyn's Star does have an extremely elliptical galactic orbit and is believed to be among the oldest stars in the galaxy and the region around it, estimated to be some 10 billion years old or older.

Very few such halo stars are located near our solar system, with such stars accounting for only 0.1 to 0.2 percent of all stars that are near the sun. Kapteyn's Star is believed to be the closest of these.  The star is a member of a local cluster of halo stars that is very thinly spread out over a distance of some 6,500 to 9,800 light-years stretching towards the galactic halo<ref>http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1996AJ....112.2661E</ref>.  Kapteyn's Star is unusual because most such stars lie far above or below the galactic plane.  Like other halo stars, Kapteyn's Star does have an extremely elliptical galactic orbit and is believed to be among the oldest stars in the galaxy and the region around it, estimated to be some 10 billion years old or older.