It is likely that recent Tenno activity has forced Eidolon to send a distress signal, attracting Sentient reinforcements that converge somewhere outside the Cetus boundary.
Hunhow may or may not be directly involved.
It is also possible that some Eidolon fragments ended up in the orbit and are trying to return to the main body.
Now imagine... Imagine them as Fissure-related, very rare, primed versions of Ayatan sculptures, tradeable, with real collector's value and none of that endo chicken feed.
Good for business, I'd wager.