Ursa Major cluster
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Ursa Major clusterAn open cluster containing over 100 stars that are scattered over an area of sky more than 1000 minutes of arc in diameter; its wide angular diameter is due to its proximity to Earth. It includes the stars Beta (β), Gamma (γ), Delta (δ), Epsilon (Ɛ), and Zeta (ζ) Ursae Majoris in the Plough, and also Sirius.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
Ursa Major cluster[′ər·sə ′mā·jər ‚kləs·tər]
An open cluster of stars, including 5 bright stars of the constellation Ursa Major, centered about 75 light-years from the sun and spread over a volume of 30 light-years length and 18-light-years width.
A cluster of galaxies in the constellation Ursa Major having a redshift of about 0.051.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.