61 Ursae Majoris

Primary of Pwyll.

61 Ursae Majoris (61 UMa) is an orange-yellow G8 main-sequence star in the constellation Ursa Major. This star is somewhat smaller and fainter than the Sun, and can just barely be seen by the unaided eye (based on a magnitude limit of 6). Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.

No substellar companions have been observed in orbit around this star, and it appears to lack a dust ring as is found around some comparable stars. It lies near the same line of sight as the sub-giant star HD 101212, although it is presently unclear whether these two stars are gravitationally bound or even in physical proximity.

The space velocity components of this star are [U, V, W] = [+8, -16, -4] km/s. It is orbiting the galaxy at a mean distance of 7.9 kpc (26 kly) from the core with an eccentricity of 0.06.