WASP-46b g'r'i'z'JHK occultation light curves

We observed a secondary eclipse of WASP-46b simultaneously in the g'r'i'z'JHK bands using the GROND instrument on the MPG/ESO 2.2m telescope. Eclipse depths of the acquired light curves were derived to infer the brightness temperatures at multibands that cover the SED peak.

We report the first detection of the thermal emission from the dayside of WASP-46b in the K band at 4.2-sigma level and tentative detections in the H (2.5-sigma) and J (2.3-sigma) bands, with flux ratios of 0.253^+0.063^_-0.060_%, 0.194+/-0.078%, and 0.129+/-0.055%, respectively. The derived brightness temperatures (2306^+177^_-187_K, 2462^+245^_-302_K, and 2453^+198^_-258_K, respectively) are consistent with an isothermal temperature profile of 2386K, which is significantly higher than the dayside-averaged equilibrium temperature, indicative of very poor heat redistribution efficiency.