A team of more than 200 researchers that includes Tabetha Boyajian, the Louisiana State astronomer that first detected the strangely dimming star that has become known as “Tabby’s Star,” and Jason Wright, the Penn State assistant professor who was part of the research team that originally posited that the star officially designated as KIC 8462852 might be partially obscured by an “alien megastructure,” has concluded that whatever happens to be causing the brightening and dimming of the star, it is most likely due to a natural, and as yet, undetected phenomenon. In short, in all likelihood, there is no Dyson’s sphere or alien megastructure around the star.
Joel Ranck of Penn State University reported (via Phys.org) this week that the star, KIC 8462852, which Boyajian herself referred to as “the most mysterious star in the universe,” had undergone intense scrutiny. The latest study derived from dedicated telescope time at Las Cumbres Observatory in Goleta, California that spanned more than eighteen months (from March 2016 to December 2017) had finally ruled out the possibility of KIC 8462852 being obscured by an alien megastructure. The new data indicates, according to Boyajian, that the “reason why the star’s light appears to dim and brighten” is dust passing between the star and the observing telescopes. This was ascertained by the different wavelengths of light that are “blocked at different intensities.”
“Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure.”
Wright, who co-authored the paper published in The Astrophysical Journal Letters, and the team found that the star became much dimmer at certain light wavelengths than at others.
“We were hoping that once we finally caught a dip happening in real time we could see if the dips were the same depth at all wavelengths, Wright said. “If they were nearly the same, this would suggest that the cause was something opaque, like an orbiting disk, planet, or star, or even large structures in space.”
The Las Cumbres Observatory data was made possible by over 1,700 donations totaling over $100,000 to purchase the dedicated time to study Tabby’s Star. The popular funding appears to have extended the involvement of citizen scientists and interested parties because the project that first detected KIC 8462852, called Planet Hunters, was a citizen scientist program designed to sift through massive quantities of data in search of planets and other anomalies.
As for the current data, there were four noticeable dimming periods detected beginning in May 2017. The authors wrote in the paper that the dips in brightness are “ancient; we are watching things that happened more than 1,000 years ago. They’re almost certainly caused by something ordinary, at least on a cosmic scale. And yet that makes them more interesting, not less. But most of all, they’re mysterious.”
The star itself has puzzled astronomers since the dimming effect was detected from Kepler Telescope data and announced in 2015. Located over 1,200 light years away, the star is relatively ordinary, about 1,000 degrees hotter than the Sun and about 50 percent bigger. Among the many hypotheses forwarded to explain the dimming and brightening — besides the highly publicized Dyson’s sphere or an alien megastructure — are a cloud of “interstellar comets,” an occluding asteroid belt, a planet, and a cloud of cosmic dust.