The most massive eclipsing binary with apsidal motion
Departament de Física, Enginyeria de Sistemes i Teoria del Senyal, Universitat d’Alacant, Alacant, Spain, and Departament d’Astronomia i Meteorologia (ICC-IEEC), Universitat de Barcelona, Barcelona, Spain
Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Bellaterra, Spain
Departament d’Astronomia i Meteorologia (ICC-IEEC), Universitat de Barcelona, Barcelona, Spain
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
Department of Astronomy and Astrophysics, Villanova University, Villanova, USA
Department of Astronomy and Astrophysics, Villanova University, Villanova, USA
Abstract
The fundamental properties of a detached and eccentric eclipsing binary (EB) with apsidal motion are presented (M31V J00442326+4127082). The system is composed by two very massive stars (with masses over 40 Mo). An additional third light is observed that could be the responsible of the discrepancy between the observed apsidal motion (of 2.4 ± 1.0 deg yr−1) and the value predicted by stellar interior models (5.4 ± 0.8 deg yr−1). However, the observed apsidal motion could be more easily explained if the stellar cores were larger than currently predicted. Therefore, additional observations of the EB presented here could be used to test the internal structure of very massive stars.