Binary stars provide a valuable test of stellar structure and evolution , because the masses of the individual stellar components can be derived with high accuracy and in a model-independent way .
In this work , we study Spica , an eccentric double-lined spectroscopic binary system with a \beta Cep type variable primary component .
We use state-of-the-art modelling tools to determine accurate orbital elements of the binary system and atmospheric parameters of both stellar components .
We interpret the short-period variability intrinsic to the primary component , detected on top of the orbital motion both in the photometric and spectroscopic data .
The non-LTE based spectrum analysis reveals two stars of similar atmospheric chemical composition consistent with the present day cosmic abundance standard defined by Nieva & Przybilla ( 29 ) .
The masses and radii of the stars are found to be 11.43 \pm 1.15Â M _ { \odot } and 7.21 \pm 0.75Â M _ { \odot } , and 7.47 \pm 0.54Â R _ { \odot } and 3.74 \pm 0.53Â R _ { \odot } for the primary and secondary , respectively .
We find the primary component to pulsate in three independent modes , of which one is identified as a radial mode , while the two others are found to be non-radial , low degree l modes .
The frequency of one of these modes is an exact multiple of the orbital frequency , and the l = m = 2 mode identification suggests a tidal nature for this particular mode .
We find a very good agreement between the derived dynamical and evolutionary masses for the Spica system to within the observational errors of the measured masses .
The age of the system is estimated to be 12.5 \pm 1Â Myr .