New paper suggests non-alien explanation for weird star behavior

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Jan 11, 2017

There's a new theory about the mysterious celestial body known as Tabby's Star.

It was last year that a controversial report from astronomer Bradley Schaefer suggested that an odd dimming effect seen around a distant sun known as Tabby's Star might have been caused by an alien megastructure -- or what we might call a Dyson sphere -- constructed around the star to collect its energy. While other, more conventional theories were also offered, such as a ring of comets circling the star, no one in the scientific community was able to say with any certainty that the star's light wasn't being blocked by artificial means.

However, a paper just published by three astronomers from Columbia University's Departments of Physics and Astronomy has now come up with a new and frankly plausible hypothesis that says the dips in the level of light emanating from Tabby's Star are being caused by the remnants of a planet that collided with it.

The paper's authors, Brian Metzger, Ken Shen and Nicholas Stone, have posited that the gradual dimming of and startling drops in light from Tabby's Star -- which have been occurring at irregular intervals since 1890 and have reached as much as 22 percent -- were the result of a planet plunging into it. The energy given off by such a collision would cause the star to shine more brightly than usual before settling down to its normal luminosity -- that would explain the object's gradual dimming over time.

As for the weird flickers observed by astronomers, those would be caused by the debris field left over from the planet -- and possibly its moons, if it had any -- passing in front of the star. And that's why the paper published by Metzger, Shen and Stone carries a lot of weight, because none of the previous theories about Tabby's Star managed to explain both the long-term dimming and the short-term flickers as this one does.

For the dimming to be seen over more than a century, the planet that theoretically fell into Tabby's Star would probably be on the larger side, increasing the chances that it took several moons with it. Some of those may have detached and are orbiting the object on their own, giving off clouds of vapor and dust due to the heat generated by their now much closer proximity to the star.

Metzger and company say that their theory can be tested when another big dip in the light from Tabby's Star is observed; if they're right, that drop-off will coincide with a huge emission of gas and dust from the debris field circling the star. In the meantime, the team's paper is currently undergoing peer review via the astrophysical journal Monthly Notices of the Royal Astronomical Society, and we have yet to hear from the Schaefer crowd with their take on it. 

Honestly, this sounds like the best explanation yet, but there's certainly a part of us that wishes it really is an alien structure out there causing all this ...

(via Gizmodo)