KIC 8462862, a distant star, flickers erratically. Among the possibilities: occlusion by an alien "megastructure" surrounding it in space.
Though it sounds far-fetched, and there's no other evidence of intelligence emanating from the system, the flickering's gotten weirder. The star's total output has diminished continuously over the course of four years.
Jason Wright, the Penn State astronomer who first suggested that Tabby's Star might be the site of a vast alien construction project, agreed that the new analysis lends credibility to Schaefer's claim of century-long dimming. "The new paper states, and I agree, that we don't have any really good models for this sort of behavior," he said. "That's exciting!"
Keivan Stassun, an astronomer at Vanderbilt who disputed the idea of long-term dimming, said that Tabby's star continues to defy explanation. "[Montet's] intriguing new findings suggest that none of the considered phenomena can alone explain the observations," he told Gizmodo. "In the end, figuring out this puzzle may require accounting for a combination of effects."
Or, they just decided to get the Dyson sphere finished ahead of schedule.
Photo from how to light objects from the inside, by Lightism.