Investigative study of five low mass ratio semi-detached binaries

Abstract

We present the first pulsation analysis of four totally eclipsing Algol systems S Cnc, SS Cet, TW And, and VW Cyg using the latest data available from Kepler (K2), and TESS databases. Based on the characteristics observed they are classified to be oscillating eclipsing Algol binaries with primary components having γ Dor type pulsations. The photometric solutions were derived for five Algols including TT Hya using Wilson-Devinney code (v2015), and the absolute parameters of all Algols in study were computed. The period variation study was also conducted using the O-C diagram and the variation is correlated either to mass loss or mass transfer or presence of third body in these systems. All the available IUE high and low resolution spectra for S Cnc, TT Hya as well as VBT and LAMOST spectra for SS Cet were used to measure the equivalent widths of prominent lines, and their significance is presented. Based on the photometric, spectroscopic, period variation, and pulsation studies the evolutionary scenario of all the five Algols is discussed using Teff - Luminosity, q-r and q-p diagrams.