Temperature of nitrogen ice on Pluto and its implications for flux
measurements

by: Tryka, K. A.; Brown, R. H.; Chruikshank, D. P.; Owen, T. C.; Geballe,
T. R.; Debergh, C.

ABSTRACT

Previous work by K. A. Tryka et al. (1993) has shown that the profile of
the 2.148-micron band of solid nitrogen can be used as a 'thermometer' and
determined the tempertature of nitrogen ice on Triton to be 38(sup 2)(sub
-1) K. Here we reevalute that data and refine the temperature value to 38
- 1 K. Applying the same technique to Pluto we determine that the tempera-
ture of the N2 ice on that body is 40 - 2 K. Using this result we have
created a nonisothermal flux model of the Pluto-Charon system. The model
treats Pluto as a body with symmetric N2 polar caps and an equatorial
region devoid of N2. Comparison with the infrared and millimeter flux
measurements shows that the published fluxes are consistent with models
incorporating extensive N2 polar caps (down to - 15 deg ot - 20 deg lati-
tude) and an equatorial region with a bolometric albedo less than or equal
to 0.2.

Icarus vol. 112, no. 2 p. 513-527 December 1994