ON THE OCCULTATIONS OF A BINARY STAR BY A CIRCUM-ORBITING DARK COMPANION

The photometric method of detecting extrasolar planets around eclipsing binaries is generally viewed as giving only a probability of occurrence of occultations by a planet. The present paper investigates the effect of precession of the planet's orbit due to the high flatness of the central body. Numerical simulations are used for a quantitative study. It is found that if a planet is present occultations necessarily occur even for inclinations of its orbital plane with respect to the binary plane as high as 20-degrees or more. For planets in close orbits around a compact binary the expectation time for occultations forced by the precession to occur does not exceed more than a few months.