SURFACE-COMPOSITION OF KUIPER BELT OBJECT 1993SC

The 1.42- to 2.40-micrometer spectrum of Kuiper belt object 1993SC was measured at the Keck Observatory in October 1996. It shows a strongly red continuum reflectance and several prominent infrared absorption f eatures. The strongest absorptions in 1993SC's spectrum occur near 1.6 2, 1.79, 1.95, 2.20, and 2.32 micrometers in wavelength, Features near the same wavelengths in the spectra of Pluto and Neptune's satellite Triton are due to CH4 on their surfaces, suggesting the presence of a simple hydrocarbon ice such as CH4, C2H6, C2H4, or C2H2 on 1993SC. In addition, the red continuum reflectance of 1993SC suggests the presenc e of more complex hydrocarbons.