S.F. Portegies Zwart and E.P.J. van den Heuvel
Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?
2015 paper referring to the 1838 to 1860-ish Eta Carinae outburst#
They propose that before 1838 (in Earth's reference frame) Eta Carinae was a triple massive star system. The 1843 outburst was the result of a merger in 1838 (which formed the ~90 MSol main star of the present system), followed by the 1843 impact of the third (non-merging) body of the initial trio with the expanded envelope of the merged star.
Interesting idea. Stimulates the obvious question of what is the prognosis?
Ohhh, I hope they passed it through a native-English speaker (or translator) before publishing things like "Also if our model would finally not be the one that explains all the chanacteristics of Eta Car, still and evolution as discribed and modelled here is expected to happen not rarely in nature."
So, what is the lookout for the future of Eta Car? Apart from "uncertain"?