Last fall, a little-known star called KIC 8462852 became our planetary obsession when astronomers said that its erratic flickering could be the result of an alien megastructure. Further observation of Tabby's Star yielded no signs of aliens, but the sudden dips in luminosity continue to defy explanation. Now, things just got a bit weirder. In an unpublished paper posted today to arXiv, Caltech astronomer Ben Montet and Joshua Simon of the Carnegie Institute describe the results of a new photometric analysis of Tabby's Star, which was first flagged in the Kepler Space Telescope's database by citizen science astronomers. By carefully examining all the full-frame images collected during Kepler's observational campaign, Montet and Simon discovered something astonishing: Not only did the star's light output occasionally dip by up to 20 percent, its totalstellar flux diminished continuously over the course of four years. For the first 1000 days of Kepler's campaign, Tabby's Star decreased in