  Pluto's two small satellites, temporarily designated S/2005 P 1 and S/2005 P
2, were observed on four dates (15.1 and 18.1 May 2005, 15.7 February 2006, and
2.8 March 2006) using the Hubble Space Telescope's (HST) Advanced Camera for
Surveys (ACS). Here we collect together the astrometric positions of these two
satellites (henceforth P1 and P2), as well as a single color measurement for
each satellite and initial constraints on their photometric variability
obtained during these observations. We find that both satellites have
essentially neutral (grey) reflectivities, like Charon. We also find that
neither satellite exhibited strong photometric variation, which might suggest
that P1 and P2 are toward the large end of their allowable size range, and
therefore may have far lower reflectivities than Charon.
