By digging through Harvard University’s archive, Bradley Schaefer, a professor of Physics and Astronomy at Louisiana State University found that between 1890 and 1989 the star had been photographed 1,200 times. By analyzing the photographs he discovered that in addition to the periodic dimming, the star has lost 20 percent of its brightness over the last hundred years.
Schaefer estimates it would require 648,000 comets, each 200 kilometers wide to block out that much light which is impossibly improbable. “The comet-family idea was reasonably put forth as the best of the proposals, even while acknowledging that they all were a poor lot. But now we have a refutation of the idea, and indeed, of all published ideas,” he says.