Light‐time effect in the eclipsing binary system AM Leonis

Abstract

Abstract. We report four new times of minimum light and the improved ephemeris for the well known contact binary AM Leo. The O-C diagram, constructed with all reliable timings found in the literature was analyzed and the the light-time effect in the system was confirmed. We found a periodicity of 44.82 years in the O-C residuals with an amplitude of 0.0058 day. The periodic curve representing the O-C values is asymmetric indicating a large eccentricity of 0.73 of the third body orbit. The mass of the third body is found to be 0.175 M for the orbital inclination of the eclipsing pair's orbit.

Radial Velocity Studies of Close Binary Stars. XII.

“…The recent period study of AM Leo (Albayrak et al 2005) shows possible cyclic period variations, interpreted by the authors as a result of a LITE caused by an invisible third component with a minimum mass of 0.18 M . The authors estimated that this hypothetical body would be about 7 mag (i.e., more than 600 times) fainter than the contact binary.…”

“…The radial velocity of the visual companion, V 3 = −11.08 ± 0.97 km s −1 , was found to be stable and close to the systemic velocity of the eclipsing binary. Due to the relatively high brightness of the eclipsing pair, it was a subject of numerous photometric investigations (for references see Hiller et al (2004); Albayrak et al (2005)). Hiller et al (2004) analyzed the light curves of the system and found q = 0.398 and the inclination angle i = 86 • .…”

Physical parameters of components in close binary systems - VII

“…They also suggested that the mass ratio is q ph = 2.51 = 1/0.398 (inverted for a W‐subtype contact binary). Albayrak et al (2005a) showed possible cyclic‐period variations, due to the existence of a third body, orbiting the contact binary in 44.82 yr and having a mass of M 3 = 0.175 M ⊙ . Qian & Yang (2005) studied the orbital variation of the system through the (O–C) diagrams.…”