I get it. The idea is a technologically advanced civilization is dumping their nuclear and radioactive waste into their sun, in effect using it as a gigantic garbage incinerator. It's actually a good idea given the problems of nuclear waste disposal, and if they are a space-faring civilization it would be efficient to do. In fact it seems to me they would have to be a very advanced space-faring civilization to create such a noticeable effect on a star. Not sure how all this could create these short life heavy elements but what the hell do I know? I would however bet there would be an anti-Sun dumping environmental movement in that civilization. :-)

The suggestion that a nearby supernova or neutron star is the culprit appears far more likely. Also, what about a small brown dwarf or a "dirty" planet orbiting the star close enough to be dumping this material?

It seems like this is something that should get more investigation than it has.