JWST finds no Dyson spheres around two candidate stars

The James Webb Space Telescope found no evidence of alien megastructures around two stars, astronomers reported on 28 July 2026.

Tabby's Star (KIC 8462852) and EPIC 204278916 had drawn attention for their irregular dimming and excess infrared radiation.

Some scientists had speculated that the signals could come from Dyson spheres — hypothetical structures built by advanced civilizations to harvest stellar energy.

But JWST's Mid-Infrared Instrument (MIRI) and Near-Infrared Camera (NIRCam) detected no artificial heat signatures. Instead, the observations point to natural causes. For Tabby's Star, a combination of dust and cometary fragments produces the infrared excess. For EPIC 204278916, the dimming is linked to a protoplanetary disk seen edge-on.

Observations took place from March to May 2026, with data analysis completed in June 2026.

The findings deliver the most definitive evidence yet that Dyson spheres are not at work around these two objects. Ruling out exotic explanations with high confidence helps astronomers focus resources on plausible phenomena.

In 2015, Tabby's Star became famous when citizen scientists noticed its erratic light dips, leading to theories ranging from comet swarms to alien megastructures. Ground-based telescopes had already cast doubt on the Dyson sphere hypothesis, but JWST's sensitivity settles the debate.

The research team now plans to use JWST to survey other stars with anomalous infrared emissions, aiming to compile a catalogue of natural explanations.