Lynga 7: Old Open Cluster or Disk Globular Cluster

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Session 103 -- Open and Globular Clusters
Display presentation, Thursday, 12, 1995, 9:20am - 6:30pm

[103.07] Lynga 7: Old Open Cluster or Disk Globular Cluster

M. Tavarez, E.D. Friel (MMO)

Lynga 7 is a richly populated Southern Hemisphere star cluster originally catalogued as an open cluster. Its location in the Milky Way and inferences about its age and composition from a recent photometric study pose interesting questions about its origin and membership in the cluster populations (Ortolani et al 1993, A\&A, 273, 415). Its location suggests membership in the disk globular clusters but its color magnitude diagram suggests an age younger than the classical globular clusters and raises the possibility that it is an extremely old open cluster. To ascertain Lynga 7's origin and membership, we have obtained moderate resolution CCD spectra from the 4 meter telescope at CTIO. From our spectroscopic study, we have derived a mean radial velocity for the cluster of 6 $\pm$ 15 km/s, and a mean metallicity of $-0.66 \pm 0.15$ dex. These results, along with its age and location in the galactic disk indicate that Lynga 7 is probably a disk globular cluster.

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