A recent paper published in Monthly Notices of the Royal Astronomical Society describes a star more than 1,400 light years away that dims and glows in a strange flickering pattern. A number of theories have been suggested to explain why this might be happening, but one of them has gained outsized public notice.
Could this be an “alien megastructure.” We don't know — but maybe?
Debra Fischer, a professor of astronomy at Yale University, is part of a project engaged in monitoring data received from the Kepler telescope — including this strange, flickering star.
“We watched the brightness of the star over time. And about four years ago, we saw a very big dip in that brightness as something was occulting or blocking part of the light from the star. And then the star was constant for a couple more years when we suddenly saw a series of sharp dips in brightness. We did everything we could to first rule out the fact that it could be an artifact or something wrong with the Kepler space craft and we're convinced that there's absolutely nothing wrong with the data. And so that leaves us trying to explain why this one star is different from the 155,000 other stars that Kepler has looked at,” Fischer says.
She and a team of scientists have come up with a number of ideas as to what might be happening near Star KIC 8462852.
“Our best guess is that it looks like a swarm of something. And so our idea, the idea that we put forward in the paper, is that this could be a swarm of comets. And my concern with that particular idea is it's not a perfect solution. The dips are very deep. They're 20 percent deep and that's maybe deeper than you'd expect to see from some cometary material. Another idea is that there've been planets that have actually collided in the system, and that we're seeing a breakup of another planet,” Fischer says.
Jason Wright, an associate professor in the department of astronomy and astrophysics at Pennsylvania State University, however, has another idea as to what might be causing the mysterious flicker.
“Whatever's passing in front of this star, there's a lot of them. They're about as big as a star. And they're not circular in aspects — they don't look anything like stars or planets. And so, until we figure this out, until we solve the mystery of what is going in front of the star, it’s basically the best candidate we have for alien life in the universe,” Wright says.
The astrophysicist still believes that a natural source likely explains the strange flickering around Star KIC 8462852. When he saw the light curves for himself, however, he started to think about other, more extraordinary explanations.
“I was at the time thinking about a prediction that had been made about 10 years ago, which pointed out that there was a long literature of ideas that perhaps alien civilizations would build giant structures — perhaps giant solar panels, maybe giant space stations, giant telescopes — there’s a lot of ideas why they would build things that are bigger than planets. And if those things exist, then an astronomer named Luke Arnold pointed out about 10 years ago that the Kepler telescope would see those things when they went in front of the star and would probably be able to tell them apart from planets,” Wright says.
Wright, Fischer, and many other scientists have already begun the work to test their theories about the star, which is over 1,400 light years away. They will begin looking for excess infrared, “thermal signatures which would come from a structure and also from a dust cloud.” They will also try to measure for distant radio signals, just in case there are any alien signals coming from the area.
What’s more, a team of telescopes from all over the world are on alert, ready to monitor the far-off light to look for the next time something passes in front of the star.
“The next time that happens it's going to be noticed,” Wright says. “We can put all of these resources back on the target. And we can actually measure the composition, or at least learn something about whatever is blocking the light. So, my hope is that at some point next year we'll see one of these dimming, and then we will all be able to figure out what this stuff is that's blocking the light. If we determine that it's ordinary astrophysical dust, we will still have a mystery, but we won't need to point radio telescopes at it any longer to look for alien signals.”
Many scientists remain excited about the possibility of an extraordinary discovery, but Wright is not convinced the flickering star is conclusive evidence we’re not alone in the universe.
“I think it's very unlikely that we've found alien life. But it is from a SETI — Search for Extraterrestrial Intelligence — perspective, it’s probably the best candidate we have,” Wright says.