A Nitrogen Rich OB Supergiant in the Large Magellanic Cloud

Abstract

Recent spectroscopic investigations of OB stars by Walborn (1970,1971a) have revealed the existence of OB stars with anomalous nitrogen and carbon spectra. In particular, two groups of stars were identified — those with strong nitrogen features and accompanying weak carbon-oxygen blends (called ON stars), and those with weak nitrogen features and strong carbon features (called OC stars). These groups bear a striking resemblance to the WN, WC dichotomy exhibited by the Wolf Rayet stars and is suggestive that a common process may be responsible for both phenomena.