Identifying and Characterising Eclipsing Binary Stars in the MOSES Survey

Abstract

This thesis presents the research methods and results from analysing data from the MOSES survey in search of variable stars. The work focuses on classifying and analysing light curves of eclipsing binary stars. Of the 33,038 stars in the MOSES survey that were analysed, 697 of them were determined to be variable objects. Using a custom written version of Phase Dispersion Minimisation (PDM), 70 of these variable objects were determined to be eclipsing binary (EB) stars, with 12 newly discovered, and their periods were subsequently determined. The EBs were analysed using PHOEBE to plot their phased light curves and determine the eclipse widths, depths of minima, and ingress and egress times. A subgroup of EBs were classified into their subclasses, resulting in 7 Algol type systems, 5 β Lyrae type systems, and 3 W UMa type systems. This subgroup was also analysed to find the ratios of the temperatures between the component stars, and the relative diameters of the components in terms of their orbital separation. For 11 of the EBs analysed in detail, TESS data are also available. The TESS data were analysed using the same methods and when compared with the results from the MOSES data there was found to be good congruence between results.