K. Pavlovski, A. Tkachenko and G. Torres (eds)
EAS Publications Series, 64 (2013) 431–432
A Day and Night on HW Vir
1 European Southern Observatory, Alonso de Córdova 3107, Santiago, Chile
2 Institute for Astronomy, K.U. Leuven, Celstijnenlaan 200D, 3001 Leuven, Belgium
3 Department of Astrophysics, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
We present a preliminary analysis of time-resolved X-shooter spectroscopy of HW Vir, a post-common envelope binary system, comprising of hot subdwarf B primary and a cool M dwarf secondary. Aiming at detecting and analysing the irradiated light of the superheated hemisphere of the M dwarf, we demonstrate that HW Vir is a bona fide double lined system allowing us to directly derive the masses of both stars and consequently backtrack the controversial evolution of subdwarf B stars and test the mass-radius relation of low mass stars.
© EAS, EDP Sciences, 2014