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We have been awarded ISO time, in the initial and suppplemental calls, to
observe a total of 5 reflection nebulae (RN), with ISOCAM and its CVF. Our
purpose is to: (1) detail the spatial distribution of specific infrared
emission features (IEFs) within each RN, and (2) explore the excitation of
IEF emission in RN over a wide range of illuminating stellar temperatures.
We have successfully detected IEFs in a RN whose central stellar system has
an ultraviolet (< 400nm) to total radiation output that is, by a factor of
two, the lowest of any stellar source yet observed to stimulate IEF emission,
a remarkable result posing problems for PAH models (Uchida et al. 1997). The
IEF emission toward vdB 133 is, however, very extended and not completely
covered by the two fields observed by ISO to date. We therefore request
discretionary time for 6 additional pointings, using ISOCAM with the LW6
filter, to complete our coverage of this region. The mosaiced ISO images will
be compared to our 12CO(2-1) molecular map of the region which show a striking
offset between molecular emission and IEF emission.