How Astronomers Plan to Solve the Mystery of the “Alien Megastructure Star”

By Corey S. Powell | July 31, 2016 11:10 pm
In the constellation Cygnus, one faint star displays enigmatic changes in brightness. Something huge is passing in front of the star–but what? (Credit: Stellaruim, Boyajian et al)

In the constellation Cygnus, the faint star formally known as KIC 8462852 displays irregular, enigmatic changes in brightness. Something huge is passing in front of the star and blocking its light–but what? (Credit: Stellaruim, Boyajian et al)

If you look in enough places, eventually you’ll find something profoundly strange. That’s been a reliable rule of thumb through the history of science, and last year it proved dramatically true again for astronomer Tabetha Boyajian. While digging through data from NASA’s Kepler space telescope, which has been monitoring 150,000 stars for signs of orbiting planets, she realized that one of these things is not like the others. A single star in that set, formally catalogued as KIC 8462852 but informally known as Tabby’s Star, flickers in an inexplicable way: unlike the shadows produced by planets, unlike any known type of stellar pulsation, simply unlike anything seen before.

Tabby’s Star is so unusual that a few scientists, including Boyajian’s colleague Jason Wright, raised the possibility that its flickering is not natural but is due to the presence of an enormous artificial construct. That speculation quickly lent KIC 8462852 another nickname, the “alien megastructure star,” and prompted a flood of breathless news stories; it even got a shout out on Saturday Night Live. Boyajian’s subsequent TED lecture drew even more attention to her star. [Update: A week after I posted this interview, Tabby’s Star star got weirder still: A new study shows that it has been inexplicably getting dimmer over the past three years.]

Now Boyajian, who recently joined the faculty of Louisiana State University, faces the daunting task of sorting through a wide range of potential explanations, from mundane to bizarre. You will probably not be surprised to hear that she’s not a big fan of the space-alien theory, but even the more sober scientific ideas are plenty exotic. I spoke with Boyajian about how she intends to solve her mystery—and about the surprising ways that institutional science is stacked against exploratory research that is not guaranteed to lead to clear answers. (For more space and astronomy news, follow me on Twitter: @coreyspowell)

When did you realize you were dealing with something profoundly strange?

There all kinds of glitches that can come up in the data, and you don’t want to spend time on something that’s just a glitch. It’s one of those things that doesn’t excite you right away. To be honest, it was the Planet Hunters [a volunteer citizen science group] who found this. When they pointed it to me, I was like, “The data’s bad, I don’t even want to look at it.” But they said, “We did preliminary tests and it checks out.” I wouldn’t have given KIC 8462852 a second look if it weren’t for that.

Tabetha Boyajian described the enigmatic "megastructure star" in a TED talk last February. (Credit: TED)

Tabetha Boyajian described the story behind the enigmatic “megastructure star” in a TED talk last February. (Credit: TED)

Then there were more checks that I did, that other people in my team did, that a few different folks at NASA did, and the Kepler team verified the data as well. It slowly built up into a love-hate relationship, because everything we learned about the star made it more difficult to understand it. Everything we observed made the star look very, very normal [except for its very, very abnormal changes in brightness]. It didn’t resemble any other class of stars that showed any kind of variability. It was a gradual learning process, learning about the star itself and checking out different theories.

What do you do when you are confronted with something like this, a star that seems to defy all the usual scientific explanations?

When you have something that doesn’t fall into any category, you start talking to people. That’s what I did, bouncing ideas off colleagues and testing out different theories. By the time we decided to write up the paper we didn’t really have any results, and this [anomalous behavior] in itself doesn’t really make an exciting paper. The way that scientists are trained, you get some data, you test out theories, you present it in a scientific paper. Writing up something like this that doesn’t have a result, only questions, is very frustrating with that mindset.

We spent a lot of time thinking about KIC 8462852. The idea was to write up everything we learned, every theory we thought of that could try to explain the star, and just present it like that. Which doesn’t make for a very exciting paper, but it is very exciting because this is something brand new. So like I said: love-hate relationship. It’s exciting but it’s frustrating at the same time. We’re looking at a new class of object, for all we know.

The tone of the news reports were not conflicted at all, of course; they were downright giddy, playing up the possibility that we were seeing an alien artifact around a distant star. How did you feel about that response?

I would definitely say it’s been overwhelming. Even in the very good articles that have been written about the star, the title is often leading. Some people don’t do responsible reporting and take it one step further. You know, it is what it is. I didn’t expect this level of excitement at all, but in retrospect I should have!

So is it this? (Credit: Danielle Futselaar/SETI International)

So is it this? (Credit: Danielle Futselaar/SETI International)

I was surprised that you didn’t approach NASA or some other big agency to help solve the mystery. Why not?

This star needs long-term, continuous monitoring, because there’s no way to predict when something’s going to happen. It’s not periodic. Government facilities don’t have the ability to do long-term monitoring. Public observatories are so well scheduled that you can get maybe three nights in a row; there’s no way to continuously monitor something on a daily basis. You could get government grants to buy time [on a private telescope network], but government grants take a long time. If I wrote a proposal now, and if we actually won, we’d get the money maybe by a year from now. Also, government grants are a very competitive process. There’s no guarantee of success, especially for a proposal like this. We’re looking at one star: high risk, high reward. That’s not something that’s appealing to the National Science Foundation.

What inspired you to launch a Kickstarter campaign? That also surprised me.

Over the past few months–ever since October when the star started being in the spotlight, really–I’ve been getting tons of emails from people asking about how they can contribute. We had a Reddit AMA, and people were offering all kinds of services: “I know nothing about science, but I can do coding work.” They wanted to be involved. Then I gave a TED talk in February, and afterward I got approached by a lot of people interested in contributing. Kickstarter was actually founded by a TED fellow. One thing led to another and this project was born.

The Kickstarter campaign captures the best of all worlds, because it lets the public still be involved. It continues the theme of outreach science, since that’s how the star was discovered. It lets us update the community on how science really works. That’s a positive thing you don’t get through government grants, which are very private.

...or is it this? (Credit: NASA/JPL-Caltech)

…or is it this? (Credit: NASA/JPL-Caltech)

So what’s the plan of attack? How will you figure out what the hell is happening around this star?

The plan is to observe the star through a full calendar year at the [private] Las Cumbres Observatory Global Telescope Network (LCOGT). We  have the funds to cover that, and a little bit more. We’re observing now, running off time LCOGT has gifted us, 200 hours there. At the end of the summer, when the Kickstarter funds get transferred, we’ll be able to set up the process through August and probably through December of 2017.

We want to see the star’s brightness dip again—it’s as simple as that. When it dips, how long the dips are, if there are many dips, all of the stuff relevant to any theory that’s on the table. Also, we’ll be able to get more detailed observations of whatever stuff is passing in front of the star, because we have a system to notify us when it’s not at its normal brightness. LCOGT is set up so we can get a spectrum as soon as that trigger happens, and also more intense observations.

If it’s not an alien megastructure passing in front of Tabby’s Star, then what is it—and how will you know?

From our new observations, we’ll be able to tell a lot about the material that’s passing in front of the star: if it’s some kind of dusty thing, some kind of solid thing. [Boyajian’s working hypothesis is that the dimming is caused by a huge swarm of comets, set loose perhaps by some cataclysmic event around the star.] What’s also important is that we will also get a baseline of spectral observations so we can look at if there’s any radial velocity shift or if there’s any variable emission of the lines, things we’d expect comets to have.

If the dimming is caused by a transiting family of comets, that would be something completely new. We’ve never seen comets go in front of a star. The dust component of comets is what you’d see in the light curve. What you’d see in the spectral observation is the gas component of comets. It would be very exciting. We’ve never even seen anything like it in our solar system or around another star. We could learn a lot from that.

What kind of signal would tell you that a comet swarm is not the answer, that you need to consider something even more exotic?

We’ll look at the orbital period [as indicated by dimming episodes that repeat]. That might lead us to favor one theory over another. Comets move on very elliptical orbits, though, and if you’re talking about a whole family of comets then individual ones may or may not transit again. That complicates things. The more dips we get the better. If they’re deeper [than what we’ve seen before], if they last longer, any of those observations will help us test out which theory is the right one.

So far, Tabby’s Star seems to be unique. How will we find out if there are others like it, or if this star is really one of a kind?

We’ve searched through the Kepler dataset and we haven’t seen anything like this star, at any level, but Kepler has only looked a little over 0.2% of the sky. There are more surveys coming out that will look at huge amounts of the sky. Now that we have the amazing properties of this one star, will we be able to set up an AI to find another star like this? Or will the next one look completely different? We just don’t know. What we do know is that if we want to find another object similar to this, we’re going to need long-time baseline data. Kepler looked for four years, and the star was doing fun stuff for only a tiny portion of that time

Well that raises an unsettling thought. What if you observe for a year and nothing happens? What if, by bad luck, you catch the star when it isn’t doing anything interesting?

We’re definitely starting to work that out. The longer we monitor the star, the better chance we have a chance to catch new details. Maybe we need something set up for the next 10 years! It’s going to take more work. The LCOGT observatory is working with us, and if we need to do another Kickstarter that can happen, even though it’s a lot of work. It’s a nail-biter.

It seems like there should be a way to carry out this kind of purely exploratory research without having to resort to Kickstarter or the like. What do you think?

Just to be clear, we have the support of tons of astronomers. Kickstarter doesn’t have to be peer reviewed, but nobody has said, this is bullshit, you can’t do that, you should be doing science. Everybody understands our point of view. The peer review process works really well overall, but it [isn’t appropriate when] the probability of having results at the end of the year is very low. Having a different, government-funded channel for scientists to do higher-risk proposals would definitely allow a lot of other cool science to get done.


  • Uncle Al

    If you look in enough different places, eventually you will find something profoundly strange.” Cerumen; nattō, khlii, surströmming, kiviak; HER; “an enormous artificial structure orbiting around the star” A civilization would never turn a profit for the initial investment of Δenergy and Δmomentum. A civilization could go Rapa Nui or Al Gore, extinguishing itself with a practical joke.

  • SFM

    We have to look no further than our Own Atmosphere to see Alien Structures. Unfortunately, even should an Alien life form present itself, Self Described Scientists would Demand proof (in triplicate) from such life forms of it’s existence! There is not a Day that goes by that someone somewhere is viewing objects which are Too advanced to be made by Humans. There are Dozens of present and prior NASA employees, including a Significant number of Astronauts who have Witnessed and/or been told by other reliable NASA employees of the existence of Craft and Structures that come and go from the Earth. These are Facts that Mainstream Media and “Science” conveniently Ignore. I find entertaining when Science is Proven Wrong, as they Rarely make a Big Deal out of their failings but Scream to the Rooftops, when they’re convinced they Really know what it is of which they speak. You can Worship at the Altar of Science, I chose not to as I and countless others around the World are Far more aware of the presence of Others who come and go, than Science may ever allow itself to see!

    • Erik Bosma

      Hahahaha…. you funny! Or maybe you funny?

      • SFM

        And Dangerous as well! I won’t be too surprised but I wish I could be there to watch you chewing what ever tongue you have, when it all Comes Out! It won’t be Long.

    • OWilson

      If there really were aliens, we would be taxing them!

      And Hillary would have a couple planted in her audience! :)

    • coreyspowell

      I have been covering NASA for three decades, have spoken to many top astronauts and astronomers, and nobody has ever mentioned any of these “facts.” I’ve also watched the dogged determination of researchers devoting their whole lives to finding evidence–anything–of life beyond Earth.

      If such evidence existed, it would instantly make its discoverer one of the most famous scientists in history. Nobody would cover up such a thing. It would be contrary to the scientific method, contrary to self-interest, and utterly contrary to human nature!

  • zlop

    Entertaining fantasizing.
    Large synthetic telescope is needed, so we can see some aliens.

  • Alexi Helligar

    Respectfully, the star’s name should probably be “Boyajian’s Star” not “Tabby Star”.

    • Martin

      My proposal is that the star be named Tabetha Boyajian, so that both your and everyone else’s name will be correct.

      • Alexi Helligar

        That’s a great solution!

  • Mike Richardson

    Nice to see that SETI is expanding to look for possible physical structures of advanced civilizations. Even if this (as is most likely) is completely natural, studying this system will give a better idea of how to rule out natural processes around another anomalous stars, giving us a better idea of how to spot any possible Dyson spheres, ringworlds, or other megastructures we haven’t even considered yet. Some have theorized lately that we may be the first advanced civilization in this galaxy, but finding evidence of engineering on such a massive scale (or absence of such) would certainly help clarify humanity’s own place in the Milky Way.

  • input@nu

    can there be another explaination? For example, the dimming of the startlight could be caused by objects that are not in orbit around the star, but passing by in front of it. That is somewhere between us and that star. Some cloud of rubble lost in space. In this way it will have nothing to do with the actual star itself.
    Or it could it be the remnants of a paired double-star or wanne be double star that never made it that far and has been desintegrated into a disk?

    • coreyspowell

      Right now every possibility is on the table, since nobody can figure this thing out. The star itself looks completely normal. The light dips are very intense but irregular and fairly brief. An intervening cloud is an interesting idea, but its properties would have to be very unusual: small enough not to affect any other star, dense enough to cause 20% light dips, clumpy enough that the dips end abruptly. Then again, no other explanation seems to fit naturally, either.

  • Denis Pozdeev

    Today Every one knows that is no fly to space and everything is fake

    • Courtney Hammett

      flat earther?

  • Carl Kruse

    Aw, couldn’t a different title been cooked up other than the hokey attention-grabbing one referring to an “Alien Megastructure,” as if there really was an alien megastructure that was discovered out there.

    Carl Kruse

  • mf2112

    Could there be a black hole as a companion, passng in front of the star causing the periodic dimming but also sucking away the star material thereby dimming it over time?

    • coreyspowell

      Interesting idea, but the pieces don’t fit together. If a black hole companion were close enough to pull material from the bright star, it would be in a very short orbit–but the light curve does not show any repeats within four years of observation. The dimming also does not seem to be related to the star itself, but to something that is passing in front of it. But what?

      • BongoBongoLA

        What if the dip #1 is a large primordial black hole passing by the system and screwing-up orbits of the planets. Then planetary collisions followed by the cluster of brightness drops about 600 or so days later.

  • RickDick

    Alien space megastructures are not new ideas. I believe it was physics populiser and co-inventor of string theory, Dr. Michio Kaku, who proposed that advanced Type III civilizations could make such huge structures. Of course alien civilizations this advanced would have to be very confident that their technology could fend off any potential adversaries alerted to their space handiwork. Perhaps such megastructures in space might even delineate areas of space territorial control. One intriguing structure, that readily stands out in the night sky, which might be an alien megastructure is the Constellation Orion. Uncanny how the three stars in Orion’s belt align diagonally and the four stars in its corners. Is this an example of an alien megastructure in space?

  • joseph2237

    Such as it is the relative flax chart does not show a mega structure. The chart does show a debris field and both planets, one original and the rogue planet that hit the the original. I see the following:
    At day 1570 is a small planet
    At day 1560 is a broken chunk from the original
    At day 1540 is the original planet.
    In between the three is debris from the accidental collision of the two.
    Either way this relative flax chart is a rare one indeed.

    Having volunteered for the citizen scientist I find it interesting how Tabetha Boyajian seems to ignore the fact that citizen scientist discovered the unusual chart and is now totally forgot after a token mention to them. The CS is scam because every time you flag a chart they come back and say they it’s their favorite chart. Total waste of time.

    • Jan Feline

      Are you aware that Dr. Boyajian is the manager of Planet Hunters?

  • joseph2237

    Two large object collided and the smaller wide signal is debris field. This is just like the collision that hit Earth and may have formed the moon. It is important to keep the observation going so we can see if two objects form or just one.

    However if the discoverer was a man it would have been universally acclaimed as a major find. But since it was a woman then we have to wait till we can squeeze a men in the mix to push her out.

    • Stephanie McNeal

      That is very sexist don’t you think. There’s brilliant woman in this world. I’m intrigued by this star, and if you take a light place it in a box and use it to create things like Morse code etc… just a thought could these dips and flickers be a type of communication???
      Or could these dips and flickers be a reflection bouncing between 2 stars? Hypothetical of course any communication could possibly be food for thought. We do not know that there is not life beyond earth. Is it possible like light houses this is a light turning which could explain the dips in light. Based on of course the day& night cycles. I’m no astronomer I’m just thinking what else could justifiably cause this type of behavior. All alien talk aside and in reality could it actually be that there truly is life beyond our own thinking? Maybe just maybe someone should test the communication theory ????:; ha ha

      • joseph2237

        No idea 7 mos ago what sexist refers to unless the author was a woman. Advanced comm between world means they don’t use radio or light. They use something more advanced. We could be talking about quantum tunneling and /or computers. Remember if “they exist” they could be on another dimension altogether. I do like the idea of a light house bc we will need more than one them when we send crews into space where they need to get back. Right now we only get to go one way

        • Stephanie McNeal

          I was referring to an old sexist post lol
          But it was just a thought on the communications side of things. Re: the strange lights and the dips in the light sequence.
          We have light houses that do the same type of dip in light as they turn in the housing units. And the dips are inconsistent throughout the days based on weather and sea conditions. So, hypothetically could it be a way of communication from beyond our thinking. Or could it be so simple we are over engineering it??!!


Out There

Notes from the far edge of space, astronomy, and physics.

About Corey S. Powell

Corey S. Powell is DISCOVER's Editor at Large and former Editor in Chief. Previously he has sat on the board of editors of Scientific American, taught science journalism at NYU, and been fired from NASA. Corey is the author of "20 Ways the World Could End," one of the first doomsday manuals, and "God in the Equation," an examination of the spiritual impulse in modern cosmology. He lives in Brooklyn, under nearly starless skies.


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