Absolute properties of BG Ind – a bright F3 system just leaving the main sequence


  • Based in part on data obtained at the South African Astronomical Observatory.

E-mail: mnr@camk.edu.pl

For the Pi of the Sky team.


We present photometric and spectroscopic analysis of the bright detached eclipsing binary BG Ind. The masses of the components are found to be 1.428 ± 0.008 and 1.293 ± 0.008 M and the radii to be 2.290 ± 0.017 and 1.680 ± 0.038 R for primary and secondary stars, respectively. Spectra and isochrone fittings coupled with colour indices calibration yield [Fe/H]=−0.2 ± 0.1. At an age of 2.65 ± 0.20 Gyr, BG Ind is well advanced in the main-sequence evolutionary phase – in fact, its primary is at TAMS or just beyond it. Together with three similar systems (BK Peg, BW Aqr and GX Gem), it offers an interesting opportunity to test the theoretical description of overshooting in the critical mass range 1.2–1.5 M.