x-ray binary variable nomenclature.

GRS 1915+15: "GRS" stands for "GRANAT source". It was discovered on August 15, 1992 by Granat.

http://en.wikipedia.org/wiki/GRS_1915%2B105

4U 1957+11:  4U means the 4th catalog.  The final version of the source catalog is known as the 4U Calalog; earlier versions were the 2U and 3U catalogs

http://www.absoluteastronomy.com/topics/Uhuru_(satellite)

gx 3+1:  gx means x-ray in the galactic coordinate, which is followed by their coordinates and has been rounded to 1 significant digit.

http://adsabs.harvard.edu/abs/1968ApJ...152.1005B

一个很好的check astronomy facts的网站。

http://www.absoluteastronomy.com/

SS 433's designation comes from its discoverers, Case Western Reserve astronomers Nicholas Sanduleak and C. Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.^[5]