Planet formation via pebble accretion in externally photoevaporating discs

Abstract We demonstrate that planet formation via pebble accretion is sensitive to external photoevaporation of the outer disc. In accretion, planets grow by accreting from a flux solids (pebbles) radially drift inwards production front. If truncates disc fast enough, it can shorten time before front reaches edge, cutting off supply for hence limiting mass reservoir growth. Conversely, cloud shielding protect strong and preserve reservoir. Because grain growth occur quickly, even on short time-scale (<1 Myr) have non-linear impact properties growing accretion. For example 10−3 M⊕ planetary seed at 25 au stays with lunar if immediately irradiated 103 G0 field, but grows migrates be approximately Earth-like in both orbital radius shielded just 1 Myr. NGC 2024, thought happen discs are <0.5 Myr old, which coupled results here suggests exact parameters very star forming environment. Universal time-scales least ∼1.5 would required completely nullify environmental architectures.