The early-type semidetached binary system V716 Centaurus

Bakis H., Bakis V., Demircan O., Eker Z.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, vol.385, no.1, pp.381-390, 2008 (SCI-Expanded) identifier identifier


New high-resolution spectra of V716 Cen revealed for the first time lines of the secondary component and its radial velocities. The simultaneous solution of the new radial velocity curves and the Hipparcos light curve yield the reliable absolute dimensions of this semidetached system. The masses for the primary and secondary are M-1 = 5.68 +/- 0.07 M-circle dot and M-2 = 2.39 +/- 0.05 M-circle dot respectively, and the radii are R-1 = 4.08 +/- 0.07 R-circle dot and R-2 = 3.36 +/- 0.02 R-circle dot. We derive also effective temperatures of T-eff1 = 15 500 +/- 50 K and T-eff2 = 9000 +/- 80 K, and equatorial rotational velocities of v(rot) sin i = 137 +/- 2 km s(-1) and v(rot) sin i = 116 +/- 7 km s(-1). These rotational velocities imply that the components rotate synchronously. The distance to the system is d = 339 +/- 8 pc, in good agreement with the less accurate Hipparcos distance (337 +/- 72 pc). The primary is underluminous and the secondary overluminous compared to normal main-sequence stars of the same mass. This implies that the secondary component of the semidetached system is in slow mass transferring stage after mass ratio reversal, although the Ha-line profiles do not show clear evidence for this.