Infrared Properties of a Large Ring Around the LBV G79.29+0.46

Abstract

G79.29+0.46 seems to be an unique object. Discovered as a nearly perfect ring in the radio continuum all subsequent observations are consistent with the interpretation that it is a large ring nebula (4‧) around an heavily reddened LBV. Our ISOPHOT and LWS observations on board of ISO show that an infrared ring coincides with the radio ring. Line emission does not contaminate the continuum images. The resulting dust temperature of > 70 K) is unusually high. The LWS spectra of the 52 and 88 µm [OIII], 63 µm [OI], 122 µm [NII] and 158 µm [CII] lines are discussed. No cool neutral gas is found near the ring. A quantitative interpretation has to await modelling of the rather complicated background.