Constraints of a pulsation frequency on stellar parameters in the eclipsing spectroscopic binary system V577 Oph

摘要

We present a preliminary spectroscopic analysis of the binary system V577Oph, observed during the summer of 2007 on the 2.6m NOT telescope on La Palma. We have obtained time series spectroscopic observations, which show clear binary motion as well as radial velocity variations due to pulsation in the primary star. By modelling the radial velocities we determine a full orbital solution of the system, which yieldsMA sin3 i = 1.562 ± 0.012 M and MB sin3 i = 1.461 ± 0.020 M. An estimate of inclination from photometry yields a primary mass of 1.6 M. Using this derived mass, and the known pulsation frequency we can impose a lower limit of 1 Gyr on the age of the system, and constrain the parameters of the oscillation mode. We show that with further analysis of the spectra (extracting the atmospheric parameters), tighter constraints could be imposed on the age, metallicity and the mode parameters. This work emphasizes the power that a single pulsation frequency can have for constraining stellar parameters in an eclipsing binary system.