Struve 2398

Struve 2398

Photo: ESO Online Digitized Sky Survey.

Struve 2398 is a binary star system, consisting of two red dwarfs, that lies only 11.5 light-years away in the northeast part of Draco (R.A. 18h 42.8m, Dec. +59° 37.8'), northeast of Xi Draconis and southwest of Delta Dra. Both stars show some variability; Struve 2398 A (spectral type M3.0, luminosity 0.00027 times that of the Sun, mass 0.36 solar mass, radius 0.54 solar radius) has been given the New Suspected Variable designation of NSV 11288, while Struve 2398 B (spectral type M3.5, luminosity 0.00013 that of the Sun, mass 0.30 solar mass, radius 0.55 solar radius) is a flare star. The system's orbit has a period of some 408 years with an eccentricity of 0.53, giving an average separation between the stars of 56 astronomical units (AU), and a range of 26–86 AU.