Cycle 2 Results

The Cycle 2 exposures, scheduled and taken before the Cycle 1 data were fully reduced, were designed to obtain maximum signal-to-noise, without ``dithering'' in the allotted spacecraft time. The images were all recorded on the same place on the PC 6 chip (to within ) and with the same roll angle. These were also double binned and co-added. the restoration results for the F718M filter (which should show a similar extended structure as the F517N images above), using an observed, composite PSF at the correct wavelength (F718M), are shown in Fig. 5. Fig. 5a is from the STSDAS V1.3 ``Lucy'' algorithm (converged to a of 1.0) and Fig. 5b from the ``MEM'' interface by Weir (1991a, b).

It is clear that the ``Lucy'' reconstruction (which converged very rapidly), shows no extended structure beyond that expected from the distortion of the aberrated PSF itself. The MEM restoration does show a hint of the type of extended structure seen in Figs. 4a and b (particularly a small feature corresponding to that marked ``2'' in 4b), but on the whole it also is disappointing. The most logical cause for this ``failure'' is simply the fact that the data for Cycle 2 are undersampled.