Space dust, not aliens: Two UW astronomers assist in new research on ‘mysterious’ star

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January 3, 2018

Turns out, it’s probably not a vast, orbiting alien megastructure that causes distant star KIC 8462852 to dim and brighten sporadically — it’s more likely just dust.
That’s the view of a new paper by Louisiana State University astronomer Tabetha Boyajian and scores of co-authors — including astronomers Brett Morris and James Davenport from the University of Washington. The paper has been accepted for publication in Astrophysical Journal Letters.
KIC 8462852 is nicknamed “Tabby’s Star” after Boyajian, who discovered it with the help of citizen scientists. The star has intrigued astronomers with its irregular, unexplained dips in light of up to about 22 percent. It’s an otherwise average star, about 1,250 light-years away, in the constellation Cygnus, and is about 40 percent more massive than the sun and about four times brighter.
The unusual dimming spawned many creative theories to explain the star’s behavior, with some hoping against all odds that the star might be orbited by a massive superstructure to harness energy  — the work of an advanced civilization. But observations from March 2016 to December 2017 from the Las Cumbres Observatory, a network of robotic telescopes, indicate the explanation is likely more prosaic than that: Space dust.
“Dust is most likely the reason why the star’s light appears to dim and brighten,” said Boyajian, an assistant professor of astronomy and physics at LSU. “The new data shows that different colors of light are being 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.”
In May of 2017, Boyajian saw that the star was again beginning to dim, and issued a call to fellow researchers to observe the star immediately. That’s where Morris and Davenport came in.
“Our involvement in this project was …

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