the way sensationalist stories like this spread is really infuriating.
astronomers discovered a star with a peculiar light curve. there is no definitive explanation for the dimming pattern. nonetheless, several hypotheses are proposed. the clickbait journalists however jump to conclusions and assume unknown = aliens. the word dyson sphere gets dropped somewhere. suddenly clickbait sites everywhere begin reporting about how astronomers have discovered a dyson sphere and so on
"alien megastructures" are one of MANY possible explanations. the truth is that we just don't know what's out there. it's almost certainly something natural but it's exciting nonetheless because it's not everyday that astronomers are baffled by something like this. there aren't a lot of things that can just block 20% of the light of a star without having other effects. it's pretty unprecedented.
still, it's best you actually READ the fucking scientific paper before you come to any conclusionshttp://arxiv.org/abs/1509.03622