Thermal Processing of Solids Encountering a Young Jovian Core

Abstract

Abstract Jupiter’s enhancement in nitrogen relative to hydrogen when compared to the Sun has been interpreted as evidence that its early formation occurred beyond the N2 snow line (∼20–40 au). However, the rapid growth necessary to form Jupiter before the dissipation of the solar nebula would lead to the forming planet’s core reaching very high temperatures (>1000 K), which would lead to it warming its surroundings. Here, we explore the effects of a luminous planetary core on the solids that it ultimately accretes. We find that a critical transition occurs where very hot (rapidly accreting) cores drive off volatiles prior to accretion, while cool cores (slowly accreting) are able to inherit volatile rich solids. Given Jupiter’s nitrogen enrichment, if it formed beyond the N2 snow line, its core could not have accreted solids at a rate above 10−10 M ⊙ yr−1. Our results suggest that either Jupiter formed in more distal regions of the solar nebula, or nitrogen loss was suppressed, either by its incorporation in more refractory carriers or because it was trapped within ices that devolatilized at higher temperatures.