Infrared excess

<p>An infrared excess is a measurement of an astronomical source, typically a <a href="/facts/Star/PFbd6ICx">star</a>, that in their <a href="/facts/Spectral_energy_distribution/6vC1Pnl6">spectral energy distribution</a> has a greater measured <a href="/facts/Infrared/44XdJNcc">infrared</a> <a href="/facts/Radiative_flux/oXqzX3Ij">flux</a> than expected by assuming the star is a <a href="/facts/Blackbody_radiation/K4YKPKXL">blackbody radiator</a>.  Infrared excesses are often the result of <a href="/facts/Circumstellar_dust/rCpC6KL0">circumstellar dust</a> heated by starlight and reemitted at longer wavelengths. They are common in <a href="/facts/Young_stellar_object/Pa6wuNkp">young stellar objects</a> and evolved stars on the <a href="/facts/Asymptotic_giant_branch/R90sd1Hl">asymptotic giant branch</a> or <a href="/facts/Post-AGB/R90sd1Hl">older</a>. 
</p><p>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 a <a href="/facts/Dyson_sphere/1xLU6xd3">Dyson sphere</a> or <a href="/facts/Dyson_swarm/1xLU6xd3">Dyson swarm</a>. This infrared excess would be the outcome of the waste heat emitted by the aforementioned structures if they are considered <a href="/facts/Blackbody_radiation/K4YKPKXL">blackbodies</a> at temperatures close to 300 K. 
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Infrared excess open-in-new

Infrared excess