The separate spectra of Pluto and its satellite Charon

The March 3, 1987 occultation of Charon by Pluto was observed spectroscopically from 5400 to 10,200 A at a resolution of 12 A. The midpoint of the event occurred at 11:06 UT; the depth of the event at 6800 A was 0.162 mag. The spectrum of Charon is completely featureless and almost perfectly flat; the red slope and the CH4 absorption features can be attributed solely to Pluto.