Observations of the interactions between binary stars provide a rich source of astrophysical data not available from isolated stars. Observations of eclipsing binaries are particularly valuable; observation of the eclipse transits provides information about the size, temperature and spectral energy distribution of the individual stars that cannot be acquired in any other way. Basic analysis can be undertaken with simple photometry, but more complete analysis has traditionally required lengthy observations with large telescopes equipped with high performance spectrographic facilities. As a result, only a few hundred eclipsing binary systems have been characterised in detail. The last thirty years has seen an increasing number of terrestrial and space-based optical time domain wide field astronomical surveys; while these are designed to target a wide variety of optically variable object types, the majority will also detect variable stars, including eclipsing binaries. Preliminary analysis of the survey data has compiled catalogues of hundreds of thousands of variable stars, many of which can be identified as probable eclipsing binaries. The single band light curves from the survey data support only the most basic characterisation (e.g. maximum magnitude; period; depth of eclipses); the limited availability of resources and observing time at fully equipped observatories means few of these new targets will be analysed in detail. This study examines the possible use of multi-band photometry using modest equipment (a 60 cm telescope with a standard CCD camera) combined with binary system modelling software, to provide a more complete characterisation of eclipsing binaries. The study presents a “proof of concept” demonstration, analysing an eclipsing binary from the WASP survey using data captured in the photometric B, V and R bands using the Open University OSO telescope, and processed with the PHOEBE binary modelling code.
Fred Vanner (Wed,) studied this question.