The Globular Cluster Pal 11

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Session 50 -- Globular Clusters
Display presentation, Wednesday, 9:20-6:30, Pauley Room

[50.07] The Globular Cluster Pal 11

S. Cersosimo, T.J. Lydon (Yale), Ata Sarajedini (NOAO), R. Zinn (Yale)

We present a color-magnitude diagram for the globular cluster Pal 11 ($\alpha = 19^{\rm h}42^{\rm m}32^{\rm s}$, $\delta=-08\deg07'$ (1950), l$~=31.8\deg$, b$~=-15.6\deg$). The cluster was observed in September 1989 and again in August 1992 using the direct CCD camera and standard B, V, and I filters on the 0.9m telescope at CTIO. From the color-magnitude diagram we determine a mean V magnitude of 17.35 for the horizontal branch (HB) and describe the morphology of the HB as a red clump of stars. These findings agree with previous investigations of the cluster. The metallicity of Pal 11 ($[{\rm Fe}/{\rm H}]=-0.23$) places it in the disk population of globular clusters which has been defined by Zinn as the clusters more metal rich than $[{\rm Fe}/{\rm H}]=-0.8$. Its distance from the galactic plane ($\vert{\rm Z} \vert \ga 3~{\rm kpc}$), however, makes it one of the most remote of the disk clusters.

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