RR Lyrae Stars in the Sagittarius Dwarf Galaxy Globular Cluster Arp 2

The Sagittarius Dwarf Galaxy is one of a few satellite galaxies of the Milky Way Galaxy. Due to the large gravitational field of the Milky Way, the Sagittarius Dwarf Galaxy is being ripped apart and absorbed into the Milky Way Galaxy. We are analyzing the globular cluster Arp 2, which once belonged to the Sagittarius Dwarf Galaxy. The DAOPHOT suite of programs was used to analyze the observations. The data were searched for RR Lyrae stars, which are pulsating variable stars, by looking for variations in the magnitudes of these stars. We were able to find several RR Lyrae stars in Arp 2. The light curves of the variable stars will be used to find the distance modulus, chemical composition, and the classification of the cluster Arp 2. Using the information found from the RR Lyrae stars, we will compare Arp 2 to other globular clusters found in the Milky Way Galaxy. By comparing the properties of a globular cluster that once belonged to an external galaxy with those in the Milky Way, we can examine in what way mergers with other galaxies helped to build up the Milky Way Galaxy