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Neptune-sized exoplanet is too big for its host star
(arstechnica.com)
I find it interesting that they didn't suggest the possibility that came to my mind first: cannibalization. If it was small to start with, but in clearing the neighborhood, also was volcanic enough to absorb smaller planetoids, it might have absorbed them and grown.
Cover author: Michał Kałużny http://astrofotografia.pl/