Anomalous far-uv extinction in the WN 6 star HD 147419.

Abstract

IUE observations of two WN stars in ring nebulae, HD 147419 and HD 89358, show that in the former star, the level of far UV interstellar extinction, λ > 1600 Å, is far higher than expected from the mean galactic extinction law. The derived scale of extinction for HD 147419, Aλ/E_B-V, agrees well with the mean galactic law at λ > 1600 Å. At shorter wavelengths a steep rise is observed, reminiscent of that found for the extinction law in the LMC and for a few galactic early-type stars. This result implies the existence of an abnormal abundance of small grains at some location in the line of sight to HD 147419, possibly in the ring nebula RCW 104 surrounding the star.