New Apsidal Motion in Four Eccentric Eclipsing Binaries: V610 Car, V944 Cep, V2815 Ori and V1260 Tau

This paper presents an apsidal motion analysis. The apsidal motion analysis of the eccentric eclipsing binaries V610 Car (P = 4.84 days), V944 Cep (P = 6.56 days), V2815 Ori (P = 2.13 days), and V1260 Tau (P = 5.43 days) was performed using minima times from the O-C Gateway database, ASAS-3, ASAS-SN, and TESS, following Lacy's approach. The rates of change of periastron longitude were found to be 0.0253 +/- 0.0041, 0.0347 +/- 0.0015, 0.0288 +/- 0.0010 and 0.0294 +/- 0.degrees 0079 cycle(-1), respectively. From the light curve study, the first photometric mass ratio of V944 Cep was found to be q = 1.4994 +/- 0.0012. A new light curve of V944 Cep was obtained using TESS data. The first absolute dimensions of V944 Cep were M (1) = 1.10 +/- 0.01 M-circle dot, M-2 = 1.64 +/- 0.02 M-circle dot, R-1 = 2.04 +/- 0.37 R (circle dot), R (2) = 3.77 +/- 0.67 R (circle dot) for the hotter primary component (T (1) = 4925 K), and M (1) = 1.04 +/- 0.01 M (circle dot), M (2) = 1.57 +/- 0.02 M (circle dot), R-1 = 2.26 +/- 0.36 R-circle dot, R-2 = 3.74 +/- 0.59 R (circle dot) for the cooler primary component (T-1 = 4475 K). For V610 Car, V944 Cep, V2815 Ori and V1260 Tau, the apsidal motion periods were found to be 188 +/- 26 yr, 186 +/- 8 yr, 73 +/- 3 yr and 182 +/- 38 yr, respectively. For V944 Cep, the internal structural constants of the component stars log(k2,obs) = -2.05 +/- 0.01 and log(k2,theo =) -1.83 for hotter primary component and log k2,obs = -1.97 +/- 0.01 and log k2,theo = -1.89 for cooler primary component were calculated.