부산대학교 도서관

We present the first high accuracy UBVRI(RI)c CCD light curves of the poorly investigated eclipsing system V680 Mon = GSC 7428 218 (P = 8.54d, V = 10.02m). They were used to find the photometric solutions and to derive the physical characteristics of the components. The highest known eccentricity e = 0.613 was found in the class of systems with eccentric orbits. The orientation of the orbital ellipse ω = 357° is not convenient for apsidal motion investigation. High accuracy of our observations allows to find the reliable parameters of the system: M1 = 3.3 (B7 V), M2 = 1.8 (A2 V). We estimate the age of the components to be 70 mega-years. The photometric parallax π = 0.00109(1)″, derived from our observations, is two times smaller than the value π = 0.0025(9)″ from GAIA DR1, affected by the presence of the K3 V optical companion of the investigated star. The light curves solution demonstrates the presence of a third light, which can be assigned to a star of A4 V spectral class. The light time effect is found in the minima timings, so the source of the third light is physically connected to the eclipsing system. The parameters of the third body orbit are derived. [ABSTRACT FROM AUTHOR]