Assertion: star's age | /r/PartOf | the group
Facets:
Source sentences:
text: Analyses in 2003 and 2005 found Sirius's membership in the group to be questionable: the Ursa Major Group has an estimated age of 500 ± 100 million years, whereas Sirius, with metallicity similar to the Sun's, has an age that is only half this, making it too young to belong to the group.