Maybe the Weird as Hell Alien Megastructures Star Ate a Planet?

Remember all the 2016 hype about alien megastructures? That was a thing. The narrative around it all gets very conspiracy theory-laden very quickly, but the gist is that a star called KIC 8462852, or Tabby’s Star, exhibits unexplained dips in its brightness, which many hopeful Earthlings have attributed to aliens. No one’s managed to find proof for that theory — or any other theory for that matter. Now, a team of scientists has put forth another, more savage hypothesis: the star’s inconsistent light output is natural, as it is going through the process of essentially digesting a large meal, like a planet. A paper outlining the research has been accepted for publication at the Monthly Notices of the Royal Astronomical Society.

When a star absorbs a large planet, or at least part of one, that planet’s energy goes in right along with it, and can thus make the star temporarily brighter. As time passes and the star digests, so to speak, that supplementary energy fades, something like the way your stomach flattens back down after a big lunch. Thus, the dimming light output of Tabby’s Star is not the result of alien megastructures intermittently blocking our view, but of the star simply returning to its unengorged natural state.

The whole thing could have taken place anywhere from 200 to 10,000 years ago — the larger the planet, the more energy it would have delivered, and the longer it would take for the star to subsequently dim. Columbia University’s Brian Metzger and his co-authors also believe such incidents might be fairly common.

“We estimated that if Tabby’s star were representative, something like 10 Jupiters would have to fall into a typical star over its lifetime, or maybe even more,” Metzger told New Scientist. “These transits only last a few days, so when we see one, we have to alert all the telescopes and basically point every telescope we have at Tabby’s star.”

To be clear, this isn’t a closed case. Conspiracy theorists will continue to conspiracy-theorize, especially any time aliens are potentially involved. But as co-author Jason Wright of Pennsylvania State University told New Scientist, the paper “puts a merger scenario on the table in a credible way …I think this moves it into the top tier of explanations.”