Evolutionary and Observational Consequences of Dyson Sphere Feedback

PSETI Seminar
Macy Huston
December 2, 2021

The search for signs of extraterrestrial technology, or technosignatures, includes the search for objects which collect starlight for some technological use, such as those composing a Dyson sphere. These searches typically account for a star's light and some blackbody temperature for the surrounding structure. However, such a structure inevitably returns some light back to the surface of its star, either from direct reflection or thermal re-emission. Due to their negative gravitothermal heat capacity, irradiated stars expand and cool, particularly in convective regions. In this talk, I will present MESA simulations used to quantify this effect in main sequence stars for a variety of Dyson sphere configurations. I will conclude with a description of when this effect matters observationally and our color-magnitude diagrams generated for a broad range of possible Dyson sphere-star systems.