Tags: Star.
V391 Pegasi also catalogued as HS 2201+2610 is a blue-white subdwarf star approximately 4570 light-years away in the constellation of Pegasus. The star is classified as an extreme horizontal branch star. It is small with only half the mass and a bit less than one-quarter the diameter of the Sun. It has luminosity 15.4 times the Sun.[citation needed] It could be quite old perhaps in excess of 10 Gyr.