I want my world to be bombarded, at a certain point of its history, by a meteor shower of iron meteors.
While analyzing the recovered samples of the meteor showers, the local scientists find proof that the meteors didn't form from planetesimals but they are fragments directly coming from the explosion of a core collapse supernova.
Assuming that their analytical techniques are on par with our state of the art today, is the above realistic?
Not directly.
The ejecta from a supernova is inevitably a diffuse plasma gas. With at most microscopic dust accretions in it. (and that only if the expanding front collides with another, stationary dust cloud)
To form iron meteors, this gas and dust would first have to have been through a cycle of planetary development, including being involved in a planetesimal of sufficient size to allow gravity-induced differentiation. I.e. something a bit larger than the asteroid Vesta. Then this planetesimal got broken up again, and formed meteors.
The planetesimal formation need not have been part of a stellar formation event, although that greatly assists in the concentration and differentiation of the materials.
