Hot Jupiter secondary eclipses measured by Kepler

Abstract

Hot-Jupiters are known to be dark in visible bandpasses, mainly because of the alkali metal absorption features. The outstanding quality of the Kepler mission photometry allows a detection (or non-detection upper limits on) giant planet secondary eclipses at visible wavelengths. We present such measurements on published planets from Kepler Q1 data. We then explore how to disentangle between the planetary thermal emission and the reflected light components that can both contribute to the detected signal in the Kepler bandpass. We finally investigate how different physical processes can lead to a wide variety of hot-Jupiters albedos.