Group Members
Current criteria for membership in the moving group is based on the stars' motion in space. This motion can be determined from the proper motions and parallax (or distance) to the stars and radial velocities. The Hipparcos satellite has recently greatly improved both the proper motion and parallax estimates of nearby bright stars, refining the study of this and other moving groups .
Based on their distances (measured with Hipparcos) and apparent magnitude, the absolute magnitude can be used to estimate the age of the stars. The stars in the moving group appear to have a common age of about 500 million years.
Read more about this topic: Ursa Major Moving Group
Famous quotes containing the words group and/or members:
“There is nothing in the world that I loathe more than group activity, that communal bath where the hairy and slippery mix in a multiplication of mediocrity.”
—Vladimir Nabokov (1899–1977)
“The damned are in the abyss of Hell, as within a woeful city, where they suffer unspeakable torments, in all their senses and members, because as they have employed all their senses and their members in sinning, so shall they suffer in each of them the punishment due to sin.”
—St. Francis De Sales (1567–1622)