The Pluto System - May 18, 2005
Although its orbit is highly eccentric, Pluto's average distance from the Sun is 39.44 Astronomical Units (A.U.) or roughly 3.6 billion miles (5.9 billion kilometers).
Pluto has a diameter of roughly 1,475 miles (2,280 km) at the equator.
These HST data are from proposal 10427: H.A. Weaver (JHU/APL), M.W. Buie (Lowell Obs.), S.A. Stern, J.R. Spencer, E. Young, and L.A. Young (SwRI); and proposal 9391: M.W. Buie and W.M. Grundy (Lowell Obs.), E. Young, L.A. Young, and S.A. Stern (SwRI). M. Mutchler (STScI) and A.J. Steffl (SwRI) are also on the science team.