Measuring Binary Parameters for Stellar Model Calibration

Stellar evolutionary models play an important role in stellar research and are used in many areas, such as Galactic modelling and exoplanet characterisation. They are often required to determine the mass and age of the planet hosting star, which are key properties needed to understand the characteristics of exoplanets. However, there are known issues with current evolutionary models, in that they can under-predict the radii and over-predict the temperatures of low-mass stars. Different models also introduce uncertainties due to the different methods of implementing parameters such as convective overshooting, mixing length and helium abundance. Further work is needed to improve the accuracy of the models and improve our understanding of how these parameters should be incorporated.
    Double-lined eclipsing binaries can be used to calibrate evolutionary models. We present the current results of a project to measure the masses and radii of four eclipsing binary systems to better that 1% accuracy, using high precision WASP photometry and high-resolution UVES spectra. With these precise values, along with effective temperatures and metallicities determined from the spectra, it will be possible to determine the age of the systems to good accuracy. This will make the stars in these binaries ideal candidates for calibrating evolutionary models.