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:
“We often overestimate the influence of a peer group on our teenager. While the peer group is most influential in matters of taste and preference, we parents are most influential in more abiding matters of standards, beliefs, and values.”
—David Elkind (20th century)
“... the theatre demanded of its members stamina, good digestion, the ability to adjust, and a strong sense of humor. There was no discomfort an actor didn’t learn to endure. To survive, we had to be horses and we were.”
—Helen Hayes (1900–1993)