Letter to the Editor

Current day mass loss rate for Luminous Blue Variable IRAS 18576+0341

¹ INAF - Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania Italy
² INAF - Istituto di Radioastronomia Sezione di Noto, CP 141, 96017 Noto (SR), Italy e-mail: g.umana@ira.inaf.it

Received: 23 February 2005
Accepted: 13 May 2005

Abstract

In this letter we report on the first set of multi-frequency and high angular resolution radio observations of IRAS 18576+0341. The radio observations have revealed an extended, asymmetric and quite structured radio nebula and allowed us to locate the central core of this highly obscured new galactic Luminous Blue Variable. From the analysis of radio properties of IRAS 18576+0341 estimates of important physical parameters of the central star have been determined. In particular, an effective temperature of , corresponding to a B0-B0.5 supergiant, has been derived. The most notable result is the determination of the current day mass-loss ( ), which is of particular importance since mass-loss rate determination from radio observations appears to be a more reliable method compared to the others based on different diagnostics.