New Constraints on Additional Satellites of the Pluto System
Abstract
Observations of Pluto and its solartidal stability zone were made using the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) on the Hubble Space Telescope on UT 2005 May 15 and May 18. Two small satellites of Pluto, provisionally designated S/2005 P1 and S/2005 P2, were discovered, as discussed by Weaver et al. and Stern et al. Confirming observations of the newly discovered moons were obtained using the ACS in the High Resolution Channel (HRC) mode on 2006 February 15 (Mutchler et al.). Both sets of observations provide strong constraints on the existence of any additional satellites in the Pluto system. Based on the 2005 May observations using the ACS WFC, we place a 90% confidence lower limit of m_{V}=26.8 (m_{V}=27.4 for a 50% confidence lower limit) on the magnitude of undiscovered satellites greater than 5" (1.1×10^{5} km) from Pluto. Using the 2005 February 15 ACS HRC observations we place 90% confidence lower limits on the apparent magnitude of any additional satellites of m_{V}=26.4 between 3" and 5" (6.9×10^{4}1.1×10^{5} km) from Pluto, m_{V}=25.7 between 1" and 3" (2.3×10^{4}6.9×10^{4} km) from Pluto, and m_{V}=24 between 0.3" and 1" (6.9×10^{3}2.3×10^{4} km) from Pluto. The 90% confidence magnitude limits translate into upper limits on the diameters of undiscovered satellites of 29 km outside of 5" from Pluto, 36 km between 3" and 5" from Pluto, 49 km between 1" and 3" from Pluto, and 115 km between 0.3" and 1" for a cometlike albedo of p_{V}=0.04. If potential satellites are assumed to have a Charonlike albedo of p_{V}=0.38, the diameter limits are 9, 12, 16, and 37 km, respectively.
 Publication:

The Astronomical Journal
 Pub Date:
 August 2006
 DOI:
 10.1086/505424
 arXiv:
 arXiv:astroph/0511837
 Bibcode:
 2006AJ....132..614S
 Keywords:

 Kuiper Belt;
 Planets and Satellites: Individual: Pluto;
 Astrophysics
 EPrint:
 Accepted by the Astronomical Journal 17 pages including 4 figures