Context:

• the mysterious dimming of Tabby’s star is caused by dust particles and not (as some believed) by alien spacecraft orbiting it.

What is Tabby’s star?

• Tabby’s star or Boyajian’s star is the “most mysterious star in the universe” as it kept dimming and brightening irregularly, following no pattern. Officially called KIC 8462852, the star is 1,000 light years away from the Earth and 1,000 degrees hotter than the Sun.

Why is it called Boyajian’s star?

• It is named after Assistant Professor Tabetha Boyajian of the Department of Physics & Astronomy, Louisiana State University. She was the main author of the paper published in 2015 that reported the reduction in the light from the star. There was a 20% decrease in brightness and the dip lasted from five to 80 days.

Have there been any other theories to explain the dimming?

• Various theories, including magnetism, gas, asteroids or collision debris have all been published. Last year, researchers from the University of Arizona had pointed out that a dust cloud could be causing the dimming.

What is the new finding?

• The recent report compiled by 133 scientists, shows that the dimming is caused by ordinary dust particles, the majority of them at a size less than one micrometre. The results were published in The Astrophysical Journal Letters.
• “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,” Dr. Boyajian says in the release.
• “They’re 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.

Source:TH