A Hot Gap Around Jupiter's Orbit in the Solar Nebula

TL;DR

The paper investigates how a hot, illuminated gap around early Jupiter's orbit in the solar nebula could have caused sublimation of icy bodies, impacting planet formation theories and the composition of primordial objects.

Contribution

It demonstrates through radiative transfer calculations that early Jupiter's gap created high temperatures capable of vaporizing icy bodies, challenging existing formation scenarios.

Findings

Temperatures in Jupiter's early gap exceeded water ice sublimation thresholds.

Icy bodies up to a meter in size vaporized within a single orbit.

High temperatures complicate noble gas enrichment and affect primordial asteroid compositions.

Abstract

The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the Solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically-thin gap in the nebula. We show using Monte Carlo radiative transfer calculations that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much further from the star, or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.