Star’s unusual dimming has been observed for the past 100 years

Ars Technica : Last year, star KIC8462852 garnered widespread press coverage because of its unusual and erratic fluctuations in brightness. Among the various theories proposed was that the dimming might indicate the actions of an advanced alien civilization. The more likely explanation, however, is that a swarm of comets and other debris in orbit around the star is blocking its light. Yet researchers using data collected by the Kepler space telescope and other observatories have not been able to corroborate that. Now, Bradley Schaefer of Louisiana State University has made the mystery of the star even deeper. Examining digitized photographic plates of sky surveys and targeted observations archived at Harvard University, he found more than 1500 images that include KIC8462852. The usable images date as far back as 1890 and reveal a pattern of behavior that can’t be explained by a comet swarm: The star has significantly dimmed in brightness over the past 100 years. Stars don’t generally grow dimmer, and the dimming that KIC8462852 experienced has been extremely variable, with a major drop in brightness followed by a partial recovery. Even alien activity can’t explain that.