AbstractsAstronomy & Space Science

A search for Long-Period Variable Stars in the Globular Cluster NGC 6496

by Mohamad Abbas

Institution: Bowling Green State University
Department: Physics
Degree: MS
Year: 2011
Keywords: Astronomy; Astrophysics; Physics; astronomy; observational; NGC 6553; globular cluster; metal-rich; variable stars; long period variable stars; mira; DAOPHOT; ALLSTAR; ALLFRAME; DAOMASTER; irregular; semi-regular; pulsation
Record ID: 1927220
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1308597257


Studying the late stages of stars is essential to understand the process of stellar evolution. Depending on their masses and properties, some stars become unstable at the end of their evolutionary state and hence they start pulsating. Their brightness and surface temperature change with their pulsations and hence we see them as variable stars. We are looking for long period variable stars (LPVs) in the globular cluster NGC 6496. We observed the cluster from February 2009 till October 2010 using a 0.41m telescope in the V and I bandpasses. We have identified 11 variable stars in the cluster. 6 of them are new discovered LPVs in which 3 of them are semiregular LPVs and the rest 3 are irregular LPVs. We plotted the color magnitude diagram (CMD) of this cluster and all our LPVs were detected on the RGB/AGB. 5 of the 11 variable stars are short period variable stars in which 4 of them are W UMa binary stars and 1 is an Algol binary star. The light curves of all these stars areplotted in this paper and the periods were detected using differentperiod-finding methods.