AAS 205th Meeting, 9-13 January 2005
Session 54 Pulsating Stars: RR Lyraes, Miras, Cepheids, etc.
Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall

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[54.03] RR Lyrae Variables in Galactic Globular Clusters

M. Catelan, R. Contreras, R. Salinas, M. E. Escobar (PUC-Chile), H. A. Smith, N. De Lee (Michigan State), B. J. Pritzl (Macalester College), J. Borissova (ESO-Chile)

RR Lyrae variables are the cornerstone of the Population~II distance scale, and yet our knowledge of the RR Lyrae variable star content in Galactic globular clusters is now known to be surprisingly incomplete. In the present paper, we present our new results in this area. Highlights of our work includes: i)~The discovery of a vast number of variable stars in M62 (NGC~6266), making it one of the three most RR Lyrae-rich globular clusters known, and also placing it as Oosterhoff type I in spite of a blue horizontal branch morphology; ii)~The determination of light curves and Oosterhoff types for globular clusters associated with the Sagittarius dSph galaxy, including NGC~5634, Arp~2, and Terzan~8; iii)~A reassessment of the variable star content in the moderately metal-rich globular clusters M69 and NGC~6304; iv)~The first theoretical calibration of the RR Lyrae period-luminosity-metallicity relation in I, J, and H, as well as an updated calibration of the K-band relation---along with comparisons against the empirical data, particularly in I.

This project was supported in part by Proyecto Fondecyt Regular 1030954.

The author(s) of this abstract have provided an email address for comments about the abstract: mcatelan@astro.puc.cl

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