We report on the detection of the secondary eclipse of the very-hot Jupiter OGLE-TR-56b from combined z ^ { \prime } -band time series photometry obtained with the VLT and Magellan telescopes .
We measure a flux decrement of 0.0363 \pm 0.0091 % from the combined Magellan and VLT datasets , which indicates a blackbody brightness temperature of 2718 ^ { +127 } _ { -107 } K , a very low albedo , and a small incident radiation redistribution factor , indicating a lack of strong winds in the planet ’ s atmosphere .
The measured secondary depth is consistent with thermal emission , but our precision is not sufficient to distinguish between a black-body emitting planet , or emission as predicted by models with strong optical absorbers such as TiO/VO .
This is the first time that thermal emission from an extrasolar planet is detected at optical wavelengths and with ground-based telescopes .