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The Vesta or Vestian family of asteroids is a large and prominent grouping of mostly V-type asteroids ("vestoids") in the inner asteroid belt in the vicinity of 4 Vesta. ==Characteristics== The Vestian asteroids consist of 4 Vesta, the second-most-massive of all asteroids (mean diameter of 530 km), and many small asteroids below 10 km diameter. The brightest of these, 1929 Kollaa and 2045 Peking, have an absolute magnitude of 12.2, which would give them a radius of about 7.5 km assuming the same high albedo as 4 Vesta. The family originated from an impact on asteroid 4 Vesta, with the giant south-polar crater the likely impact site. The family are thought to be the source of the HED meteorites. The Vesta family also includes a few J-type asteroids (related to the V-type), which are thought to have come from the deeper layers of Vesta's crust, and are similar to the diogenite meteorites A HCM numerical analysis by (Zappala 1995) determined a large group of 'core' family members, whose proper orbital elements lie in the approximate ranges This gives the approximate boundaries of the family. At the present epoch, the range of osculating orbital elements of these core members is The Zappala 1995 analysis found 235 core members. A search of a recent proper-element database ((AstDys )) for 96944 minor planets in 2005 yielded 6051 objects (about 6% of the total) lying within the Vesta-family region as per the first table above. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Vesta family」の詳細全文を読む スポンサード リンク
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