The secondary eclipse of the transiting exoplanet CoRoT-2b

TL;DR

This study detects the shallowest secondary eclipse of exoplanet CoRoT-2b, measuring its depth and temperature, providing insights into its atmospheric properties and albedo.

Contribution

First detection of the shallowest secondary eclipse of CoRoT-2b, with temperature and albedo estimates derived from high-precision light curve analysis.

Findings

Secondary eclipse depth of 0.0060% detected

Planet's surface temperature estimated at ~1910 K

Upper limit for geometric albedo is 0.12

Abstract

We present a study of the light curve of the transiting exoplanet CoRoT-2b, aimed at detecting the secondary eclipse and measuring its depth. The data were obtained with the CoRoT satellite during its first run of more than 140 days. After filtering the low frequencies with a pre-whitening technique, we detect a 0.0060$\pm$0.0020% secondary eclipse centered on the orbital phase 0.494$\pm$0.006. Assuming a black-body emission of the planet, we estimate a surface brightness temperature of T$_{\rm p,CoRoT}$=1910$^{+90}_{-100}$ K. We provide the planet's equilibrium temperature and re-distribution factors as a function of the unknown amount of reflected light. The upper limit for the geometric albedo is 0.12. The detected secondary is the shallowest ever found.