Kahraman Aliçavuş, F. ; Handler, G. ; Aliçavuş, F. ; De Cat, P. ; Lampens, P. ; Ekinci, O. ; Gumus, D. ; Leone, F.

Talk presented at Turkish Physics Society 37th International Physics Congress (Bodrum, Turkey) on 2021-09-03

Abstract: Oscillating eclipsing Algols (oEA) are semi-detached systems including one main-sequence B-F pulsating star and one evolved component which transfers its matter to the pulsating component through the 1st Lagrangian point. As we are able to obtain precise fundamental stellar parameters (mass, radius) with the simultaneous analysis of radial velocity changes and binary light curves, these systems are beneficial to examine the binary evolution and their pulsations in great detail. In this study, we introduce the results of our comprehensive photometric and spectroscopic analysis of the oEA system TZ Dra. As a result, we derived the fundamental stellar and atmospheric parameters and investigated the pulsational variations. The Halpha lines show clear evidence of mass transfer in the system. The mass transfer/loss from the system was supported with the orbital period variation analysis. We derived a mass loss rate of 3.52x10−10 M⊙/year for TZ Dra. The matter leaves the system most probably through the hotspot on the primary component and winds. The analysis of pulsations also revealed that the system is a tidally tilted pulsator.