[JimRed]

Regular cycles of dimming can be due to a large planet or dark companion star passing between the star and the telescope. But that theory would not tend to justify more grants to “study” it...

[Red Badger]

....or a fly on the lens................

[mcshot]

The cycles of dimming are neither regular nor predictable.

[ctdonath2]

Yes, that’s sensible.
Except that the pattern of occlusion has to fit within certain physical limits, which apparently this pattern isn’t.
... Unless it’s artificial, which this pattern suggests it is.

[piasa]

If there’s more than one dark companion in different orbits it would make for more irregular cycles.