Assertion: asterism's star | /r/CapableOf | share common birth
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Source sentences:
text: Mizar and Alcor's proper motions show they move together, along with most of the other stars of the Big Dipper except Alpha Ursae Majoris and Eta Ursae Majoris, as members of the Ursa Major Moving Group, a mostly dispersed group of stars sharing a common birth.