# Direct rocky planet formation without protostellar disk?

Can a rocky planet form directly from the collapse of an interstellar gas cloud?

The picture I have of rocky planet formation is that dust and rocky material in a protostellar disk accumulates into a rocky planet. There must be some mechanism to prevent the accretion of significant amounts of (hydrogen/helium) gas, I'm guessing this is something to do with the gas either being unable to cool, reheated if it does cool, or outright removed from some region around the protostar as the stellar wind and/or radiation pressure kick in.

My intuition is that even the most metal enriched (astronomer metal, i.e. everything heavier than $\rm{He}$) cloud still by far hydrogen dominated, so that a cloud in isolation must always form a primary star/brown dwarf/gas giant. But has anyone ever heard of a mechanism where a cloud in the right environment (some radiation field that efficiently heats the gas but not the dust/metals perhaps?) could form a rocky body directly, with no associated star? This seems far fetched, but I'm curious to know whether anyone has ever looked at this; literature references appreciated.