Long Period Variable Stars in the Globular Cluster M5

TL;DR

This study conducted VI time series photometry of globular cluster M5, identifying known variables and discovering thirteen new low-amplitude long period variables, enhancing understanding of stellar variability in dense clusters.

Contribution

It provides new observations and discoveries of low-amplitude long period variables in M5, expanding the catalog of variable stars in this cluster.

Findings

Recovered all known bright variables in M5

Discovered thirteen new low-amplitude LPVs

Analyzed periods and amplitudes of variable stars

Abstract

We report results of VI time series photometry for the bright globular cluster M5 taken between 2007-2011 using the 0.5-m telescope at Bowling Green State Univ. and the PROMPT #4 telescope at Cerro Tololo. We used DAOPHOT to obtain photometry to a limiting magnitude of V~19 mag. A search for variable stars using the DAOMASTER variability index enabled us to recover the three known bright variables (two Cepheids and one red, long period variable, or LPV) and many known RR Lyrae stars, and to discover as many as thirteen new, low-amplitude LPVs. We present light curves of several stars and analyze periods and amplitudes where applicable.