Fig. 12. Spectrum Shapes Resulting from Wavelength-Variable Emissivity. 
12a shows the variation in emissivity with wavelength that is necessary
to produce a typical warm Ganymede spectrum from an isothermal surface
at 155oK. The dashed line on 12b shows the effective temperature
vs. spectrum slope trend produced by an isothermal surface at varying temperatures,
with this same wavelength-dependent emissivity. The spectrum slope decreases
steadily with decreasing temperature, unlike the Voyager1 Ganymede data
that is also shown.
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