《ms0507-Conroy+Murphy》.pdfVIP

Journal of the Southeastern Association for Research in Astronomy, 5, 34–42, 2012 February 1 c 2012. Southeastern Association for Research in Astronomy. All rights reserved. VARIABLE STARS IN THE GLOBULAR CLUSTER M14 Kyle E. Conroy1 Department of Astronomy and Astrophysics, Villanova University, Villanova, PA, 19085 and Andrew N. Darragh, Zheyu J. Liu, and Brian W. Murphy Department of Physics and Astronomy, Butler University, Indianapolis, IN, 46208 ABSTRACT Using an image subtraction method we have searched for variable stars in the globular cluster M14. We confirmed 62 previously known catalogued variables. In addition to the previoulsy known variables we have identified 71 new variables. We have confirmed the periods of most of the cataloged variables with just a few exceptions. Of the the total number of confirmed variables, we found a total of 112 RR Lyrae stars, several of which exhibited the Blazhko Effect. Of the total we classified 55 RR0, 57 RR1, 19 variables with periods greater than 2 days, a W UMa contact binary, and an SX Phe star. We present the periods of previously found variables as well as the periods, classification, and lightcurves of the newly discovered variables. Subject headings: stars: variables: general–Galaxy: globular clusters: individual: M14 1. INTRODUCTION previous photographic studies. In doing so, we have con- Globular clusters provide a laboratory for studying firmed many of the pre