A new study addsfuel to the fiery debate raging between astronomers abouta possible alien megastructure built around a star 1,480 light-years away.In case you missed it, the star, KIC 8462852 (otherwise known as Tabby), has been causing a stirsince last October, when a team of astronomers suggested the faint possibilitythat the strange dips they'd observed in the star's brightness could be attributed toextraterrestrial life.Thislatest paper lends some support to astudy which originally discredited the alien megastructure idea. That studysuggested that comets, not aliens, wereresponsible for the eerie dimming.ADyson swarmYale astronomer Tabby Boyajianand, Penn State astronomer Jason Wright and colleagues posted their paperabout KIC8462852 onApril 14, 2015. The paper was publishedon arXiv, an online archive where researchers can submitscientific paperswithout being peer reviewed.It found uneven dips in the brightness of the star based on observations from citizen scientists. This suggested that irregularly shaped objects passing across the face of the star were temporarily blocking some of its light.The scientists put forward several explanations for this observation, but one from Wright stuck out. Hesuggested that an intelligent alien civilization could be in the process of building an enormous shell of megastructures around thestar as a means ofharvestingits energy. The hypothetical collection of constructsis known as a Dyson swarm.Since then,scientists have been scrambling to make sense of these strange findings.Scientists atSETI (Search for Extraterrestrial Intelligence) Internationalnot to be confused with the SETI Institute who wereinvestigatingthe star found the star system to be awfully quiet with no unnatural signals coming from it.Theyoffered a new explanation:a giant swarm of comets passing in front of the sun produced the fluctuations of light. But in January, a study released by Louisiana State University astronomer Bradley Schaefersaid the comet explanation didn't workbecause Tabby's star had steadily dimmedover the last century by as much as 20%. That sort of dimming would require some648,000 giant comets, Schaefer estimated.Not verylikely. Alas, the alien megastructure idea re-emerged.Another twist in the plotBut another new paperhasfound a problem with Schaefer's data: Itrelied on information froma bunch ofdifferent instruments. And that alone couldexplain the 20% dip in brightness he measured, these researchers say. For their latest study, two research teams took a lookat the brightness of other stars like Tabbys star, and they found that during the same period, their brightnesses dimmed too. Tabby was not alone. And this dimming, theyconcluded,was simply the result ofa change of telescopes that happened around 1962.The new results also give some new support to the comet hypothesis, since they suggest that only36 comets are neededexplain the dips in brightness(a much morereasonable number than the 648,000 figure that Schaefer proposed in January).Aliens or not, Tabby's star remains "the most mysterious star in the universe" as Boyajian said ina TED talk.SEE ALSO:That bizarre-looking star just got a lot weirder ' and yes, it could be aliensDON'T MISS:We spoke with the astronomers who discovered the 'alien' megastructure to find out if it's fact or fictionJoin the conversation about this storyNOW WATCH: That bizarre-looking star just got way more mysterious ' and aliens could be the reason
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