EDP Sciences
Free access
Volume 437, Number 1, July I 2005
Page(s) L1 - L5
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200500126

A&A 437, L1-L5 (2005)
DOI: 10.1051/0004-6361:200500126


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

G. Umana1, 2, C. S. Buemi2, C. Trigilio2 and P. Leto2

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 )

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 $T_{\rm eff} \sim (2.6 \pm 0.2)$ $\times$ $10^{4}~{\rm K}$, corresponding to a B0-B0.5 supergiant, has been derived. The most notable result is the determination of the current day mass-loss ( $\dot {M}= 3.7$ $\times$ $10^{-5}~M_{\odot}~{\rm yr}^{-1}$), 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.

Key words: circumstellar matter -- stars: winds, outflows -- stars: mass-loss -- radio continuum: stars -- stars: individual: IRAS 18576+0341, AFGL 2298

SIMBAD Objects in preparation

© ESO 2005