Barnard's Star

Motion of Barnards Star captured: left 1997 (Jack Schmidling), right 1950 (POSS)

Right Ascension	17:58 (h:m)
Declination	+04:41 (deg:m)
Distance	5.97 (ly)
Visual brightness	9.56 (mag)
Spectral type	M3.8V

Also cataloged as Munich 15040 or LFT 1385, Barnard's Star was discovered in 1916 by E.E. Barnard to have the largest known proper motion of all stars, 10.29 arc seconds per year, by comparing photographic plates obtained in 1894 and 1916, and later tracing it back to 1888 in E. Pickering's plate archive. This star moves apparently fast between the background stars in Ophiuchus, needing only about 350 years for 1 degree, in almost exactly North direction (Burnham gives a position angle of 356 degrees).

This star is the second nearest to our Solar System at 5.97 light years, only triple star Alpha Centauri is closer. From this distance, it follows that the fast apparent motion corresponds to an unusually high velocity. In addition, this star is approaching us rapidly at 87 miles per second, so that the combination of both indicates a space velocity of of about 103 miles per second. According to Burnham, the star will reach a minimum distance of less then 4 light years in about 8,000 years, when its proper motion will have reached 25 arc seconds per year and its brightness will be about magnitude 8.6.

Barnard's star is a red main-sequence dwarf of apparent visual magnitude 9.56 and absolute visual magnitude +13.4. Its luminosity is only about 1/2500 that of our sun. According to Burnham, J.C. Duncan has estimated the star's mass as 16 percent that of our sun, and its diameter at 224,000 km (140,000 miles) or about 1/6 that of our sun. Its spectral type indicates that Barnard's Star is cool: Only about 3200 K.

It was longly tried to investigate this star's motion for perturbations due to planet-sized companions, and P. van de Kamp had announced the discovery of the presence of at least one planet of 1.5 times the mass of Jupiter at a separation of 2.4 arc seconds, or 4 Astronomical Units. However, after a decade-long discussion, this discovery could still not be verified, and more recent observations with the Hubble Space Telescope have not yet given evidence of any large planet near this star.

Images by amateur astronomer Jack Schmidling and the Digital Sky Survey.