16 Psyche is theorized to be the remnant iron core of an early small protoplanet that might have had it's surface and mantle stripped away through violent asteroid impacts.
Some modeling of possible magnetic fields and solar wind disruptions from 16 Psyche have already been performed in this paper. Here is one of their figures:
This question is a follow on to this idea: Place a satellite at Sun-Mars L1 to shield Mars from Sun radiation . If we could put the enormous iron asteroid 16 Psyche at Mars L1 and spin it up, could we shield Mars from solar winds?