Tabby's star dims again

The team of astrophysicists studying KIC 8462852, more well known as Tabby's star, has reported that the star recently dimmed again, and did so quite dramatically. The group, led by LSU's Tabby Boyajian who discovered the odd behavior of the star back in 2015, has been documenting their findings on their web site.

Tabby's star has been under study for many years, as one of a group of stars known to dim—space scientists are interested in such stars, because in most cases, they have planets transiting them, dimming their light. But KIC 8462852 is different, Boyajian noticed—it dimmed a lot more than other stars did—at one point, as much as 20 percent. That was too much to chalk up to a planet blocking its light. Also, the star tended to stay dim for longer periods of time than other dimming stars. So she and others wondered what could be causing the dimming.

Researchers advanced many theories, such as aliens building a Dyson sphere, but most were shot down. The most likely explanation, Boyajian has suggested, is dust. She and her team found earlier this year that the light that makes its way to us from the star is of different wavelengths at different times, which, she notes, suggest that it is passing through something translucent, casting serious doubts on the Dyson sphere theory. She and her team have proposed several theories regarding the nature of the dust, most involving the idea of planets or other objects colliding. One notable exception is the possibility of a comet that was torn apart as it approached the star.

In this latest report, the star was seen to dim on March 16—a dip that Boyajian reported was the largest observed since 2013 (she and her team went back and looked at old Kepler data after the star was found to dim abnormally). By the March 22, the star was nearly back to its normal brightness. In the same blog post, she reminded readers that the observation was made possible by donations to the Kickstarter campaign set up for just this purpose, and while that project has ended, she is still requesting donations.

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