0 Assigned ID: 377 ----- Attempting Submission 1 (Fri Apr 10 06:23:50 GMT 2015) ----- HST Phase I Proposal 377 (ContributionFunctions_APT.apt) successfully submitted. Receipt: # 377-1 ----- Attempting Submission 2 (Fri Apr 10 20:09:05 GMT 2015) ----- The physics of condensate clouds pose one of the greatest challenges to our understanding of brown dwarfs, transiting hot jupiters, and directly imaged exoplanets. The combination of HST's unique sensitivtity and photometric precision enables powerful time-resolved observations of rotating ultracool atmospheres and in 9 recent programs using 128 orbits 44 brown dwarfs and exoplanets have been observed in full or partial rotations. These data are leading to breakthroughs in our understanding of condensate clouds. The broad wavelength coverage of HST/WFC3 provides a particularly powerful probe of the atmospheres as different wavelengths probe different layers in the atmospheres, typically between 0.1 mbar and 20 bar. Therefore, rotational phase mapping observations at multiple layers can be translated to multi-layer maps, i.e., longitudinal-vertical maps of the atmospheres. Such maps are key to testing and developing a general cloud model valid for ultracool atmospheres. However, no database or model grid is currently available to easily translate the collected light curves into pressure levels or to plan observations of specific pressure levels. We propose here to calculate contribution functions (emerging flux as a function of pressure and wavelength) for a uniquely large grid of model atmospheres. The contribution functions will provide a direct, easily applicable tool to: 1) translate existing and future rotational phase maps of ultracool atmospheres to longitudinal-vertical cloud maps; 2) plan the optimal observing strategy for future HST and JWST observations. We will also apply the tool to published HST observations to link variability amplitude to pressure levels. EXTRA-SOLAR PLANETS 0 Regular false false false false true SUPPORTED