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  • There's an unsolved mystery out there in space.

  • One of many, to be sure, but this is one that some people really want to blame on aliens

  • because we haven't had a stronger explanation.

  • I'm talking about Boyajian's star, or KIC 8462852 and some new observations that

  • may have just given us the information we need to say with certainty: Aliens!?

  • Or no?

  • Boyajian's Star, previously referred to as Tabby's star, is named after the astrophysicist

  • who first studied its inexplicable behavior.

  • It's a bit larger than our own sun, and is about 1300 light-years away.

  • And it displays behavior that we just can't figure out.

  • Actually, it's the most unusual dimming of a star ever observed.

  • Its brightness dips in totally erratic and unpredictable ways.

  • Sometimes just a tiny bit, sometimes by as much as 22 percent.

  • And here's the thingthese behaviors can't be attributed to most of the things you would

  • think of.

  • The dimming is much too substantial to be caused by an orbiting planet, because even

  • planets as big as the biggest ones in our solar system would only make a tiny blip in

  • the brightness of Boyajian's star.

  • Plus, if it were a planet, we should be seeing the same dip in brightness at regular intervals

  • as the planet runs rings around that star, but no.

  • Maybe it was a swarm of comets careening toward the star.

  • But then astronomers found that the star actually has been dimming steadily for years in

  • addition to the unpredictable blips in brightnessit's losing its shine, and it's about 14% less

  • bright than it was a century ago.

  • A comet cloud couldn't cause something that gradual.

  • So the lack of any convincing explanation for its finicky behavior is what gave rise to

  • this idea of energy-generating alien technology, like a Dyson sphere, which I think is pretty hilarious.

  • It is indeed very tempting to think that the unpredictable dimming of this star is due

  • to some alien megastructure passing in front of it to gather power.

  • But a new model from Columbia University may just give us an answer that doesn't rely

  • on the existence of a hyper-developed solar-powered alien civilization.

  • The new theory says that maybe Boyajian's star has been a little bad.

  • Like the villain in a Charles Dickens novel, it may have stolen an orphaned exomoon.

  • This hypothesis is based on the idea that the star pulled a moon into its orbit from

  • a now long-gone planet, and the poor moon is now being torn apart by stellar radiation

  • that it wasn't used to in its previous life, orbiting merrily around a planet.

  • The resulting plumes of debris from the moon's outer layers blow off into the solar system,

  • coming in between the star and Earth, causingfrom our perspectivethe occasional, unpredictable

  • dips in brightness.

  • But what makes this theory so tantalizing is that it also explains the gradual wane

  • in brightness.

  • As more and more of the moon breaks up, the larger, heavier chunks are getting pulled

  • into orbit with what remains of the original exomoon.

  • This forms a disk of debris that sticks around, dimming the star's light over time.

  • Using models of both exomoon detachment dynamics and obscuration of stellar light, the team

  • has compiled some pretty convincing evidence for this hypothesisand it's certainly

  • at least a little more credible than the idea of alien technology.

  • But we still need a bigger sample size to come to any hard conclusions

  • And we're in luck, because it turns outBoyajian's star has friends!

  • A new study surveyed more than 14 million stellar objects, and found 21 stars that also

  • might display unusual, unexplained dips in brightness.

  • The hope is that this data will allow us to study these bodies, and look for clues to

  • see if the same mechanism is behind each of their blinking and winking, and if so, if

  • it just might be this orphaned exomoon theory.

  • That sounds like a pretty cool job.

  • If you want even more on some crazy behavior of stars that we're just beginning to uncover,

  • watch this video here, and subscribe to Seeker for all your stellar exploration news.

  • Let us know what other space mysteries you want us to cover in the comments below, and

  • as alwaysthanks for watching.

There's an unsolved mystery out there in space.


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B1 中級

タビーの星が奇妙に見える理由を明らかにする新説 (A New Theory Reveals Why Tabby’s Star Looks So Bizarre)

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    林宜悉 に公開 2021 年 01 月 14 日