A new study has provided astronomical evidence that the strange dimming star KIC8462852 has been doing so — dimming, that is — for over a century, not to mention sporadically dimming at times as well, thus mathematically ruling out the prevailing favorite theory that the loss of brightness is due to an erratic swarm of comets in the extrasolar system. At the same time, the study’s authors note that the phenomenon is likely caused by some type of physical mechanism, which again regenerates the idea that the star may be experiencing an occlusion caused by what has been popularly referred to as an “alien megastructure.”
New Scientist reported January 15 that astrophysicist Bradley Schaefer of Louisiana State University, after studying data from star KIC8462852 that dates back as far as 1890, mathematically concluded that, for the erratic dimming of the star, there would have had to have been at least 648,000 comets, each approximately 200 kilometres wide, to have passed by the star, He says that the numbers are completely implausible.
“The comet-family idea was reasonably put forth as the best of the proposals, even while acknowledging that they all were a poor lot,” Schaefer says. He, of course, was speaking of the Yale University study headed by Tabetha Boyajian (where the star gets its informal name, Tabby’s Star), which proposed the swarm of comets theory. “But now we have a refutation of the idea, and indeed, of all published ideas.”
And since the dimming has continued for over a century, Schaefer also contends that the “alien megastructure” theory runs counter to his observations, because he does not believe an alien civilization could have constructed something capable of obscuring one-fifth of a star in a century. However, Jason Wright, who led the Penn State University team that posited the Dyson sphere-based theory of an alien megastructure surrounding KIC8462852, finds that all Schaefer has excluded with his studies is dimming of the star not being caused by a natural effect.
Schaefer says in the paper, “The century-long dimming and the day-long dips are both just extreme ends of a spectrum of timescales for unique dimming events, so by Ockham’s Razor, all this is produced by one physical mechanism. This one mechanism does not appear as any isolated catastrophic event in the last century, but rather must be some ongoing process with continuous effects.”
The anomaly that is star KIC8462852 has become a much-studied entity. The idea that the dimming effect could be a product of an alien civilization was pursued by the newly founded SETI (Search for Extraterrestrial Intelligence) International — not to be confused with the California-based SETI Institute. A team led by astronomer Doug Vakoch trained its sights on the star last year, searching for radio and/or visible waves that might indicate an alien civilization. However, the study returned no positive results.