Rho Ursae Majoris

Rho Ursae Majoris (ρ UMa) is the Bayer designation for a solitary star in the northern circumpolar constellation of Ursa Major. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74. The distance to this star, based upon an annual parallax shift of 10.37 mas, is around 315 light years.

With a stellar classification of M3 III, this is a red giant star on the asymptotic giant branch. It is a suspected small amplitude variable. The measured angular diameter of the star after correcting for limb darkening is 6992273434916145778♠5.64±0.15 mas, which, at the estimated distance of this star, yields a physical size of about 58 times the radius of the Sun. It is radiating 464 times the solar luminosity from its outer atmosphere at an effective temperature of about 3,725 K. Based upon its motion through space, there is a 60.6% chance that this star is a member of the Sirius stream.