Published online by Cambridge University Press: 14 August 2015
The spectra of a variety of Wolf-Rayet stars have been observed with ∼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 0 VI star ST 3 shows very strong C IV lines like the WC5 stars but not the strong He I.