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Thursday 28 May 2009: What eclipsing binaries and transiting planets tell us about stars
Dr Leslie Hebb - University of St. Andrews
Physics, 4th Floor interaction area 12:00-13:00
Recent wide field, ground based, time-series photometry surveys have lead to the discovery of many intrinsic variable stars including new eclipsing binary stars, transiting planet host stars, and rotational variables. In this talk, I will present new variable objects that have been identified as part of the the SuperWASP, ASAS or Monitor time-domain surveys and discuss what we are learning about the properties and characteristics of stars through the analysis of these objects. Detached eclipsing binary stars provide the most accurate measurements of intrinsic stellar properties including masses, radii, temperatures and absolute luminosities for two component stars with the same ages and metallicities. I will discuss the importance of obtaining measurements of stellar masses and radii, the outstanding problems that exist between the empirical measurements and the theoretical models, and my attempts to obtain new measurements of the masses and radii of young stars and very low-mass objects through the detection and analysis of eclipsing binaries. I will also discuss how the analysis of transiting extra-solar planets can be used to learn about the host stars themselves. Analysis of transiting planets provide a different set of host star properties than eclipsing binaries, particularly the mean stellar density and effective temperature. I will compare these parameters to existing theoretical stellar evolution models and discuss the results in the context of outstanding issues with the models. Finally, I will discuss new rotational variables identified in young, nearby star forming associations that we are using to put constraints on the timescales for disc locking in young stars as a function of spectral type.
