  Water absorption is identified in the atmosphere of HD209458b by comparing
models for the planet's transmitted spectrum to recent, multi-wavelength,
eclipse-depth measurements (from 0.3 to 1 microns) published by Knutson et al.
(2007). A cloud-free model which includes solar abundances, rainout of
condensates, and photoionization of sodium and potassium is in good agreement
with the entire set of eclipse-depth measurements from the ultraviolet to
near-infrared. Constraints are placed on condensate removal by gravitational
settling, the bulk metallicity, and the redistribution of absorbed stellar
flux. Comparisons are also made to the Charbonneau et al. (2002) sodium
measurements.
