Wolf 359 - Observation History and Name

Observation History and Name

Wolf 359 first came to the attention of astronomers because of the relatively high rate of transverse motion against the background, known as the proper motion. A high rate of proper motion can indicate that a star is located nearby, as more distant stars must move at higher velocities in order to achieve the same rate of angular travel across the celestial sphere. The proper motion of Wolf 359 was first measured in 1917 by German astronomer Max Wolf, with the aid of astrophotography. In 1919 he published a catalog of over one thousand stars with high proper motions, including this one, that are still identified by his name. He listed this star as entry number 359, and the star has since been referred to as Wolf 359 in reference to Max Wolf's catalogue.

The first parallax measurement of Wolf 359 was reported in 1928 from the Mount Wilson Observatory, yielding an annual shift in the star's position of 0.409 ± 0.009 arcseconds. From this position change, and the known size of the Earth's orbit, the distance to the star could be estimated. It was the lowest-mass and faintest star known until the discovery of VB 10 in 1944. The infrared magnitude of the star was measured in 1957. In 1969, a brief flare in the luminosity of Wolf 359 was observed, linking it to the class of variable stars known as flare stars.