A new analysis highlights red dwarfs and white dwarfs as the best places to search for hypothetical alien megastructures known as Dyson spheres. The research outlines distinct infrared signatures and unusual light patterns that could reveal such structures. It also notes that existing telescope data already contains several unconfirmed candidates.
Amirnezam Amiri of the University of Arkansas examined how a Dyson swarm would alter a star's appearance on the Hertzsprung-Russell diagram. The structures would absorb visible light and re-emit energy as infrared heat, shifting the apparent temperature of the host star as low as 50 kelvin while keeping its luminosity unchanged.
Red dwarfs stand out because their small size allows a swarm to orbit at distances between 0.05 and 0.3 astronomical units, requiring less material. White dwarfs offer even smaller orbital scales of a few million kilometers due to their compact size.
The study adds that a genuine swarm would lack the silicate dust signatures typical of natural stars and could produce irregular brightness changes as its components orbit. Observations from the James Webb Space Telescope and earlier WISE mission data are well suited to detect these features.
In 2024, Project Hephaistos identified seven candidate stars, five of which remain under review after one was attributed to a background black hole.