Seven candidate Dyson spheres found from their excess infrared radiation could be a case of mistaken identity, with evidence for dusty background galaxies spotted close to three of them.
The seven candidates were discovered by Project Hephaistos, which is coordinated by astronomers at Uppsala University in Sweden and Penn State University in the US.
A Dyson sphere is a hypothetical construct: a swarm of energy collectors capturing all of a star’s radiant energy to provide huge amounts of power for its builders. As these energy collectors – basically huge arrays of solar panels – absorb sunlight, they must emit waste heat as infrared radiation to avoid overheating. While a complete Dyson swarm would hide a star from view, this waste heat would still be detectable.
The caveat is that to build a complete Dyson swarm, a lot of raw material is required. In his 1960 paper describing the concept, Freeman Dyson calculated that dismantling a gas giant planet like Jupiter should do the trick.
Given that this is easier said than done, Project Hephaistos has been looking for incomplete Dyson swarms “that do not block all starlight, but a fraction of it,” says Matías Suazo of Uppsala University, who is leading the project.
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