Search for extrasolar trojans.A Search for Exotrojans in Transiting Exoplanetary systems

A Search for Exotrojans in Transiting Exoplanetary systems
http://arxiv.org/abs/0807.4570

Abstract wrote:

We present a search for Trojan companions to 25 transiting exoplanets. We use the technique of Ford & Gaudi 2006, in which a difference is sought between the observed transit time and the transit time that is calculated by fitting a two-body Keplerian orbit to the radial-velocity data. This technique is sensitive to the imbalance of mass at the L4/L5 points of the planet-star orbit. No companions were detected. The median 2$\sigma$ upper limit is 60 Earth masses, and the most constraining limit is 2.5 Earth masses for the case of GJ 436.

The systems they checked were
XO-3, HAT-P-3, WASP-2, HAT-P-2, TrES-4, HAT-P-5, CoRoT-Exo-2, WASP-1, WASP-3, TrES-3, CoRoT-Exo-1, XO-2, WASP-5, WASP-4, HAT-P-7, HD 189733, TrES-2, HAT-P-4, HD 149026, HD 17156, TrES-1, HD 209458, and Gliese 436.