Struve 2398 is also called Sigma 2398, BD+59°1915, DM+59°1915, and Gl 725, and informally Proxima Draconis. It is a nearby binary red dwarf system. The distance of the two component stars was first measured by Friedrich von Struve in 1832. Star A is also known as HD 173739. It is inaccurarely referred to as a K type star in some catalogs. Star B is also known as HD 173740. Their distance ranges from 19 to 65 AU. An observer from Star A would see Star B as a point about as bright as the full moon.