A&A 427, 193-197 (2004)
Discovery of multiple shells around V838 MonocerotisJ. Th. van Loon, A. Evans, M. T. Rushton and B. Smalley
Astrophysics Group, School of Chemistry and Physics, Keele University, Staffordshire ST5 5BG, UK
(Received 15 April 2004 / Accepted 3 July 2004 )
We report the discovery of multiple shells around the eruptive variable star V838 Mon. Two dust shells are seen in IRAS and MSX images, which themselves are situated in a shell of CO. This securely establishes V838 Mon as an evolved object. We revisit the light echo, which arises from scattering off the innermost resolved dust shell, to infer a distance to V838 Mon of 5.5 kpc. The dynamical timescales of the ejected shells, location in the Milky Way and inferred luminosity are consistent with V838 Mon being a low-mass AGB star experiencing thermal pulses of which the 2002 eruption might have sent the star into the post-AGB phase. This scenario, however, is inconsistent with the presence of a (young and massive) B3 V companion.
Key words: stars: AGB and post-AGB -- stars: circumstellar matter -- stars: distances -- stars: individual: V838 Monocerotis -- stars: mass-loss -- stars: peculiar
© ESO 2004