Aninfrared excess is a measurement of an astronomical source, typically astar, that in theirspectral energy distribution has a greater measuredinfraredflux than expected by assuming the star is ablackbody radiator. Infrared excesses are often the result ofcircumstellar dust heated by starlight and reemitted at longer wavelengths. They are common inyoung stellar objects and evolved stars on theasymptotic giant branch orolder.[1]
In addition, monitoring for infrared excess emission from stellar systems is one possible method that could enable a search for large-scale stellar engineering projects of a hypothetical extraterrestrial civilization; for example aDyson sphere orDyson swarm.[2] This infrared excess would be the outcome of the waste heat emitted by the aforementioned structures if they are consideredblackbodies at temperatures close to 300 K.[3][4]
