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Stellar Populations and Variable Stars in the Core of the Globular Cluster M5

L. Drissen·M. M. Shara
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Abstract

We report the discovery of a variable blue straggler in the core of the globular cluster M5, based on a 12-hour long series of images obtained with the Planetary Camera aboard the Hubble Space Telescope. In addition, we present the light curves of 28 previously unknown or poorly studied large-amplitude variable stars (all but one are RR Lyrae) in the cluster core. A (V, U-I) color-magnitude diagram shows 24 blue stragglers within 2 core radii of the cluster center. The blue straggler population is significantly more centrally concentrated than the horizontal branch and red giant stars.

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L. Drissen, M. M. Shara. 1997-11-13. Stellar Populations and Variable Stars in the Core of the Globular Cluster M5. https://doi.org/10.1086/300197

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