The first UV spectrum of 2060 Chiron*

Abstract

Chiron was observed for the first time in the UV, approximately one year before its perihelion passage, with the IUE satellite. Three long-wave, low-dispersion spectra were obtained, representing a total exposure of 56400s. The spectra contain useful information, though with very low S/N ratio, longward of ~2550A. No emission from gaseous species was detected. The total flux in two UV bands and in the Voyager PPS band was determined and used together with the adopted radius for Chiron (90 km) to derive the UV albedo. Chiron has a significant UV albedo, similar to that of some Saturnian and Uranian satellites. The UV albedo shows an upturn in the UV range, reaching ~0.27 near 2700A, qualitatively similar in behaviour to that of some laboratory ices and outer Solar system icy bodies. The UV/IR colour and UV albedo are very similar to those of Dione.