Twin stars as tracers of binary evolution in the Kepler era

We present results of the combined photometric and spectroscopic analysis of four systems that are eclipsing binaries with a twin component (mass ratio q ≃ 1). These are exceptional tools to provide information for probing the internal structure of stars. None of the systems were previously recognized as twin binaries. We used a number of high-resolution optical spectra to calculate the radial vel...