Search for Planetary Candidates within the OGLE Stars

We propose a method to distinguish between planetary and stellar companionsto stars which present a periodic decrease in brightness, interpreted as atransit. Light curves from a total of 177 stars from the OGLE project werefitted by the model which simulates planetary transits using an opaque disk infront of an image of the Sun. The simulation results yield the orbital radiusin units of stellar radii, the orbital inclination angle, and the ratio of theplanet to the star radii. Combining Kepler's third law with a mass-radiusrelation for main sequence stars, it was possible to estimate values for themasses and radii of both the primary and secondary objects. This model wassuccessfully tested with the confirmed planets orbiting the stars HD 209458,TrES-1, OGLE-TR-10, 56, 111, 113, and 132. The method consists of selecting asplanetary candidates only those objects with primary densities between 0.7 and2.3 solar densities (F, G, and K stars) and secondaries with radius less than1.5 Jupiter radius. The method is not able to distinguish between a planet anda dwarf star with mass less than 0.1 $M_\odot$, such as OGLE-TR-122. We proposea selection of 28 planetary candidates (OGLE-TR-49, 51, 55, 63, 71, 76, 90, 97,100, 109, 114, 127, 130, 131, 134, 138, 140, 146, 151, 155, 159, 164, 165, 169,170, 171, 172, and 174) for high resolution spectroscopy follow up.Comment: 4 figures, 2 table