This is the arXiv doc cited and there is no any "alien" word or theory in it:
https://arxiv.org/pdf/1608.01316v1.pdf
There are several theories, of which the alien structure one is the less probable:
https://en.wikipedia.org/wiki/KIC_8462852
The pics posted are in fact about the other theories.
For nice sci-fi pictures, the non-scientific daily mail article got quite a few cute ones:
'Dyson sphere' star found to be dimming dramatically - and nobody knows why | Daily Mail Online
I would be really surprised if that was an alien thing.
