Six new eccentric eclipsing systems with a third body

Abstract

We present the discovery of six new triple stellar system candidates composed of an inner eccentric-orbit eclipsing binary with an apsidal motion. These stars were studied using new, precise TESS light curves and a long-term collection of older photometric ground-based data. These data were used for the monitoring of ETVs (eclipse timing variations) and to detect the slow apsidal movements along with additional periodic signals. The systems analysed were ASASSN-V J012214.37+643943.3 (orbital period 2.01156 d, eccentricity 0.15, third body with 3.3 yr period); ASASSN-V J052227.78+345257.6 (2.42673 d, 0.35, 3.2 yr); ASASSN-V J203158.98+410731.4 (2.53109 d, 0.20, 2.7 yr); ASASSN-V J230945.10+605349.3 (2.08957 d, 0.18, 2.3 yr); ASASSN-V J231028.27+590841.8 (2.41767 d, 0.43, 4.9 yr); and NSV 14698 (3.30047 d, 0.147, 0.5 yr). In the system ASASSN-V J230945.10+605349.3, we detected a second eclipsing pair (per 2.99252 d) and found adequate ETV for the pair B, proving its 2+2 bound quadruple nature. All of these detected systems deserve special attention from long-term studies for their three-body dynamics since their outer orbital periods are not too long and because some dynamical effects should be detectable during the next decades. The system NSV 14698 especially seems to be the most interesting from the dynamical point of view due to it having the shortest outer period of the systems we studied, its fast apsidal motion, and its possible orbital changes during the whole 20th century.