New Period Investigation of Algol-like Near-Contact Binary EG Cephei
| Authors | |
|---|---|
| Year of publication | 2009 |
| Type | Article in Periodical |
| Magazine / Source | PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN |
| MU Faculty or unit | |
| Citation | |
| Field | Astronomy and astrophysics |
| Keywords | stars: binaries: eclipsing; stars: evolution; stars: individual (EG Cephei) |
| Description | The Algol-like Near Contact Binary EG Cephei was observed in 2008 October. All of the available eclipse times, including 735 epochs, spanning more than 100 years were analyzed. A period oscillation with a period of 35.8 (+-0.1) yr and an amplitude of about 0.0037(+-0.0002)d was found, while undergoing a secular increase at a rate of dP/dt = 3.4 x 10e-8(+-0.1) d/yr. This continuous period increase may be caused by mass transfer from the secondary component to the primary one on a thermal timescale, which is consistent with the Algol-like semi-detached configuration of EG Cep. Combining with the spectroscopic and photometric results, we derived a conservative mass-transfer rate of this target, dM/dt=3.0(+-0.1)x10e-8 Mo/yr. The oscillation part of the period variation may be the result of a light-time effect due to the existence of a coplanar additional body with a mass of M3 = 0.11Mo, and a corresponding radius of a3 = 14AU. |
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