Alien megastructures are back in the headlines after some new research published last week. It has been claimed that Tabby's Star is confirmed to be steadily dimming, which is completely unexpected behavior for a star. Prof Kipping explains what we know (and don't know) about this mysterious star and what astronomers really mean by "alien megastructures". ::More about this Video:: ► Montet & Simon (2016), "KIC 8462852 Faded Throughout the Kepler Mission": http://arxiv.org/abs/1608.01316 ► Schaefer (2016), "KIC 8462852 Faded at an Average Rate of 0.165+-0.013 Magnitudes Per Century From 1890 To 1989": http://arxiv.org/abs/1601.03256 ► Boyajian et al. (2016), "Planet Hunters X. KIC 8462852 - Where's the Flux?": https://arxiv.org/abs/1509.03622 ► Arnold (2005), "Transit Lightcurve Signatures of Artificial Objects": http://arxiv.org/abs/astro-ph/0503580 ► Kipping & Teachey (2016), "A Cloaking Device for Transiting Planets": http://arxiv.org/abs/1603.08928 ► Outro music by Taylor Davis: https://www.youtube.com/watch?v=dl9kI1yQKZk ::Playlists For Channel:: Latest Cool Worlds Videos ► http://bit.ly/NewCoolWorlds Cool Worlds Research ► http://bit.ly/CoolWorldsResearch Guest Videos ► http://bit.ly/CoolWorldsGuests Q&A Videos ► http://bit.ly/CoolWorldsQA Science of TV/Film ► http://bit.ly/ScienceMovies ::Follow us:: SUBSCRIBE to the channel http://bit.ly/CoolWorldsSubscribe Cool Worlds Lab http://coolworlds.astro.columbia.edu Twitter https://twitter.com/david_kipping Instagram https://www.instagram.com/cool.worlds THANKS FOR WATCHING!!