Exoplanet Discoveries and Updates

[The Astronomer]

Hmm, yeah, Hermeans and Ferrinians need to either be merged or separated distinctly. I say Ferrinians are those so-called 'cannonballs' with a ridiculous iron fraction of like over 80% mass or so, as described. It seems very difficult to form one.

I think that "cannonball" planets are possible to form in at least one way, which I saw in a really old Poul Anderson story. "Mirkheim", I think. Very simply, a perfectly normal planet subjected to a nearby supernova and all but an iron core is boiled off. In that story, it was worth exploiting as a source of superheavy elements.

Another way for something like this to happen is a fairly normal Jovian which is perturbed out of its normal orbit into a star-grazing one and most of its mass similarly boiled off.

Still, without either scenario being plausible in this system (the second would probably result in a silicate core anyways), it's kind of hard to imagine something happening that would result in an Earth-massed cannonball, especially in a tightly-packed system like this one...