Secondary eclipses in the CoRoT light curves: A homogeneous search based on Bayesian model selection

TL;DR

This study systematically searches for secondary eclipses in CoRoT exoplanet light curves using Bayesian model selection, confirming some known eclipses and discovering new significant events.

Contribution

It introduces a uniform Bayesian approach to detect and characterize secondary eclipses across all published CoRoT planets, improving consistency and sensitivity.

Findings

Confirmed eclipses for CoRoT-1b and CoRoT-2b.

Detected significant eclipses for CoRoT-6b, CoRoT-11b, and CoRoT-15b.

Found marginal evidence for eclipses in several other CoRoT planets.

Abstract

We aim to identify and characterize secondary eclipses in the original light curves of all published CoRoT planets using uniform detection and evaluation critetia. Our analysis is based on a Bayesian model selection between two competing models: one with and one without an eclipse signal. The search is carried out by mapping the Bayes factor in favor of the eclipse model as a function of the eclipse center time, after which the characterization of plausible eclipse candidates is done by estimating the posterior distributions of the eclipse model parameters using Markov Chain Monte Carlo. We discover statistically significant eclipse events for two planets, CoRoT-6b and CoRoT-11b, and for one brown dwarf, CoRoT-15b. We also find marginally significant eclipse events passing our plausibility criteria for CoRoT-3b, 13b, 18b, and 21b. The previously published CoRoT-1b and CoRoT-2b eclipses are also confirmed.