The pictures are pretty, but what can we learn from them? I poked around on the website of the Space Telescope Science Institute to see if I could figure out what scientific purpose lay behind the transit photos. Here is the abstract of the proposal from a team of scientists led by Keith Noll:
We propose a program of 39 orbits to observe 6 targets with WFPC2 following a successful return to science using side B electronics. These observations will be used for Hubble Heritage releases in the months leading up to servicing mission 4 [currently scheduled for May 12, 2009]. Because of launch delays, our reserve of releasable images is growing dangerously slim. We are proposing here to replenish one of our important lines of communication with the public.
We have carefully chosen targets that can efficiently use single pointings of WFPC2 to obtain images of visually striking and astrophysically interesting targets. Observations will reach high S/N [signal to noise] and will be dithered and subsampled to improve the resolution and pixel scale to near ACS/WFC3 quality at a modest cost in exposure time. Most of the observations will schedule in the interim between a return to science and the availability of new science proposals that may be selected in response to an interim call for proposals.