VLT transit and occultation photometry for the bloated planet CoRoT-1b

We present VLT eclipse photometry for the giant planet CoRoT-1b. We observed a transit in the R-band filter and an occultation in a narrow filter centered on 2.09 μm. Our analysis of this new photometry and published radial velocities, in combination with stellarevolutionary modeling, leads to a planetary mass and radius of 1.07 +0.13 −0.18 MJup and 1.45 +0.07 −0.13 RJup, confirming the very low density previously deduced from CoRoT photometry. The large occultation depth that we measure at 2.09 μm (0.278 +0.043 −0.066 %) is consistent with thermal emission and is better reproduced by an atmospheric model with no redistribution of the absorbed stellar flux to the night side of the planet.

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