Fig. 2.

Nebular-captured hydrogen envelopes for a Mars size and mass object at 1.5 AU, in units of Earth ocean equivalent amounts of hydrogen ($1{\mathrm{EO}}_{\mathrm{H}}=1.53\times {10}^{23}\mathrm{g}$) as a function of luminosity for three different dust grain depletion factors f=0.001 (dashed-dotted line), f=0.01 (dashed line), and f=0.1 (dotted line).