The Mystery of Tabby’s Star

  • By Ana Aceves
  • Posted 05.23.18
  • NOVA

Tabby’s star flickers erratically and no one knows why—could it be an alien megastructure?

Running Time: 03:18


The Mystery of Tabby’s Star

Published May 23, 2018

Onscreen: Tabetha Boyajian is trying to solve the mystery of a very weird star.

Tabetha Boyajian: I worked with dozens of other astronomers for several years, trying to figure out what could be causing these strange fluctuations in its light.

Narrator: Is it caused by an asteroid belt? Or colliding planets?

Boyjian: So, we had this long list of ideas. None of them worked.

Narrator: Then, one of Tabby’s colleagues offers a possible idea, a bit outside the standard astronomy box…

Boyjian: When I showed him this star he said “Wow, this is really weird, and we don’t have an explanation for it.” He said, “These things all look like they could be caused by some artificial alien megastructure.”

Narrator: …an artificial alien megastructure, a giant structure built by a hypothetical alien civilization to harness the energy from its own sun. When the word gets out…

Reporter 1: Talk about the prospects of an alien megastructure…

Reporter 2: …evidence of alien life.

Reporter 3: The strange light pattern makes it seem more like a death star planet rather than a star.

Boyjian: This star loves attention, and it makes everybody crazy.

Narrator: It is farfetched. To dim a star by so much, an alien megastructure would have to be at least half as big as the star itself. But, when the theory is first proposed, astronomers can’t rule it out.

Boyjian: Something is happening with our star here. We sent off alerts via Twitter, and data of all sorts started coming our way. At this point, it’s like we’re swimming in data.

Narrator: Tabby and her team at Louisiana State are looking for patterns in the color data that could tell them what kind of material is passing in front of the star.

Boyjian: Blue light and red light will react differently to material that’s passing in front of the star.

Narrator: Whatever is passing in front of Tabby’s star appears to be blocking more blue light than red and orange light. But what would block out more blue light? Tabby has a theory: space dust.

Boyjian: Dust scatters blue light more than it does red light. And so, that indicates that there’s some sort of dusty semi-opaque, you know, material that’s crossing in front of the star and blocking out its light.

Tabetha Boyjian’s Student: It’s got the signatures of being dust, rather than, it’s…can’t be some kind of opaque object, like a planet or an alien megastructure?

Boyjian: That’s right.

Narrator: The culprit is likely scattered dust, and not a solid alien megastructure. But the mystery is hardly solved. What created this giant cloud of dust? Why is it centered around Tabby’s star?

Boyjian: Nature is a lot more creative than we are, and you know, we’re just going to have to, you know, really buckle down and try and, and figure this one out.



Digital Producer
Ana Aceves
Produced, and Directed by
Jane Teeling and Phil Bertelsen
© WGBH Educational Foundation 2018

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