The candidate luminous blue variable G79.29+0.46: A comprehensive study of its ejecta through a multiwavelength analysis

Abstract

We present a multiwavelength analysis of the nebula around the candidate luminous blue variable G79.29+0.46. The study is based on our radio observations performed at the Expanded Very Large Array and at the Green Bank Telescope and on archival infrared data sets, including recent images obtained by the Herschel Space Observatory. We confirm that the radio central object is characterized by a stellar wind and we derive a current mass-loss rate of about 1.4 × 10-6M⊙ yr-1.We find the presence of a dusty compact envelope close to the star, with a temperature between ̃40 and 1200 K. We estimate for the outer ejecta an ionized gas mass of 1.51M⊙ and a warm (60-85 K) dust mass of 0.02M⊙. Diagnostics of the far-infrared spectra indicate the presence of a photodissociation region around the ionized gas. Finally, we model the nebula with the photoionization code CLOUDY, using as input parameters those estimated from our analysis. We find for the central star a luminosity of 105.4 LM⊙ and an effective temperature of 20.4 kK. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.