Hill Stability Limits for Prograde and Retrograde Exomoons as a Function of Planetary Separation

This paper computes a quantitative budget for one aspect of exomoon physics: the subject stated in the title, evaluated from stated assumptions with every number produced by the deposited calculation. Headline results are hill_jupiter_1AU_km = 1.021e+07; prograde_limit_km = 4.999e+06; retrograde_limit_km = 9.507e+06; retro_pro_ratio = 1.90; jupiter_1AU_Hill_radii = 0.0. The Hill sphere sets the outer boundary inside which a planet, rather than its star, governs the motion of a satellite. For an exomoon the question is sharper than the formal definition suggests, because long-lived orbits occupy only a fraction of that sphere: numerical integrations by Domingos and collaborators showed that prograde satellites remain bound only within about forty-nine per cent of The results are compared with published Solar System values and with the constraints attached to reported exomoon candidates where those apply, and the conditions under which the computed budget would change are stated explicitly. Computed from stated assumptions, not measured.