From dust to planets – I. Planetesimal and embryo formation

Planet formation models begin with proto-embryos and planetesimals already fully formed, missing out a crucial step, the of planetesimals/proto-embryos. In this work, we include prescriptions for planetesimal proto-embryo arising from pebbles becoming trapped in short-lived pressure bumps, thermally evolving viscous discs to examine sizes distributions throughout disc. We find that increase orbital distance, ~10 km close star hundreds kilometres further away. Proto-embryo masses are also found radius, ranging $10^{-6} M_{\rm \oplus}$ around iceline, $10^{-3} near orbit Pluto. pebble accretion can attain. Close star, is efficient due small planetesimals, whilst where fragmentation limited, but inefficient when drift dominated low rates before supply diminishes. Exterior becomes increasing eccentricities, more as initial increase, allowing them significantly grow depleted. Combining both scenarios allows massive at larger distances, since become efficient, giant planet cores form distances upto 10 au. By including realistic sizes, well combined scenarios, should allow complete understanding beginning end process how planets planetary systems form.