Hot super-Earths and giant planet cores from different migration histories

Understand

Planetary embryos embedded in gaseous protoplanetary disks undergo Type I orbital migration.

• Migration can be inward or outward depending on the local disk properties but, in general, only planets more massive than several $M_\oplus$ can migrate outward.
• Here we propose that an embryo's migration history determines whether it becomes a hot super-Earth or the core of a giant planet.
• Systems of hot super-Earths (or mini-Neptunes) form when embryos migrate inward and pile up at the inner edge of the disk.