Climate modelling of hypothetical moon-moons in the Kepler-1625b system

Abstract

If the exomoon candidate orbiting Kepler-1625b truly exists, it is much more massive than the moons observed in the Solar system (Teachey et al. 2017; Teachey & Kipping 2018). This exomoon would be sufficiently large to stably host its own satellite. This has sparked discussion of a new category of celestial object - a moon-moon (Forgan 2018) or submoon (Kollmeier & Raymond 2018). In this Note, I describe initial results of climate modelling of a hypothetical moon-moon in the Kepler-1625b system, calculated using the OBERON code, which jointly computes 1D latitudinal energy balance models for individual worlds alongside the dynamical evolution of the system they inhabit (Forgan 2016a, DOI:10.5281/ZENODO.61236). Both the code and the parameter files used in these runs are available at github.com/dh4gan/oberon.