Alien megastructures are out. The unusual fading of an oddball star is more likely caused by either clouds of dust or an abnormal cycle of brightening and dimming, two new papers suggest.
Huan Meng of the University of Arizona in Tucson and his colleagues suggest that KIC 8462852, known as Tabby’s star, is dimming thanks to an orbiting cloud of fine dust particles. The team observed the star with the infrared Spitzer and ultraviolet Swift space telescopes from October 2015 to December 2016 — the first observations in multiple wavelengths of light. They found that the star is dimming faster in short blue wavelengths than longer infrared ones, suggesting smaller particles.