A modified CoRoT detrend algorithm and the discovery of a new planetary companion

Abstract

We presentMCDA, a modification of the COnvectionROtation and planetary Transits (CoRoT) detrend algorithm (CDA) suitable to detrend chromatic light curves. By means of robust statistics and better handling of short-term variability, the implementation decreases the systematic light-curve variations and improves the detection of exoplanets when compared with the original algorithm. All CoRoT chromatic light curves (a total of 65 655) were analysed with our algorithm. Dozens of new transit candidates and all previously known CoRoT exoplanets were rediscovered in those light curves using a box-fitting algorithm. For three of the new cases, spectroscopicmeasurements of the candidates' host stars were retrieved from the ESO Science Archive Facility and used to calculate stellar parameters and, in the best cases, radial velocities. In addition to our improved detrend technique, we announce the discovery of a planet that orbits a 0.79-0.09+0.08 R⊙ star with a period of 6.718 37 ± 0.000 01 d and has 0.57-0.05+0.06 RJ and 0.15 ± 0.10MJ. We also present the analysis of two cases in which parameters found suggest the existence of possible planetary companions.