GSC 4019 3345: An A-Type Twin Binary

Physical dimensions and evolutionary status of the A-type twin binary GSC 4019 3345 are presented. Located at a distance of similar to 1.1 kpc from the Sun, the system was found to have two components with identical masses (M-1,M-2 = 1.92 M-circle dot), radii (R-1,R-2 = 1.76 R-circle dot), and luminosities (log L-1,L-2 = 1.1 L-circle dot) revolving in a circular orbit. Modeling the components with theoretical evolutionary tracks and isochrones implies a young age (t = 280 Myr) for the system, which is bigger than the synchronization time scale but smaller than the circularization time scale. Nevertheless, synthetic spectrum models revealed components' rotation velocity of V-rot12 = 70 km s(-1), that is about three times higher than their synchronization velocity. No evidence is found for an age difference between the components.