Mayall II = G1 in M31: Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy?

  title={Mayall II = G1 in M31: Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy?},
  author={Georges Meylan and Ata Sarajedini and Pascale Jablonka and S. George Djorgovski and Todd S. Bridges and Robert Michael Rich},
  journal={The Astronomical Journal},
?????At the moment, only the anticorrelation of metallicity with age recently observed in ? Centauri suggests that this cluster enriched itself over a timescale of about 3?Gyr. This contradicts the general idea that all the stars in a globular cluster are coeval and may favor the origin of ? Centauri as being the remaining core of a larger entity, e.g., of a former nucleated dwarf elliptical galaxy. In any case, the very massive globular clusters, by the mere fact that their large masses imply… 

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