Infrared (1.4-4.1μm) spectra of Wolf-Rayet stars

The spectra of a variety of Wolf-Rayet stars have been observed with approximately 1% spectral resolution in the 1.4-4.1μm region using UKIRT. Strong lines due to ions of helium and carbon are observed and their relative strengths discussed. The He I singlet at 2.058μm is anomalously strong relative to other He I lines in WC stars and is responsible for the difference in the (H-K) colours of WN and WC stars. Emission line corrections to H, K and L magnitudes of different types are discussed. The Sanduleak O VI star ST 3 shows very strong C IV lines like the WC5 stars but not the strong He I. (Auth.)