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:
“Caprice, independence and rebellion, which are opposed to the social order, are essential to the good health of an ethnic group. We shall measure the good health of this group by the number of its delinquents. Nothing is more immobilizing than the spirit of deference.”
—Jean Dubuffet (1901–1985)
“This will not be disloyalty but will show that as members of a party they are loyal first to the fine things for which the party stands and when it rejects those things or forgets the legitimate objects for which parties exist, then as a party it cannot command the honest loyalty of its members.”
—Eleanor Roosevelt (1884–1962)