Galactic globular clusters are among the oldest population of
the Universe. Their studies are of particular interest to know about
the evolution history of the Milky Way. In a globular cluster, most
commonly found variables are RR Lyrae stars (‘‘cluster-type’’ variables).
RR Lyrae being short period variables are easy to detect by
means of observational data of few hours. They have long been
used as standard candles, making the distance estimation of a cluster
possible. Studying their pulsational properties enables the
astronomers to probe the internal structure of the stars. They are
particularly important to study the evolution of low mass stars.
RR Lyrae also play important role in studying the horizontal branch
(HB) morphology of the globular cluster (Newsham, 2007).