Strong asymmetries in the neutral envelope of Mira *
CO and K I observations
E. Josselin 1,2,
N. Mauron 2,
P. Planesas 1 and
R. Bachiller 1
Received 12 April 2000 / Accepted 4 July 2000
We present high-resolution observations of the neutral envelope of o Ceti. The molecular component has been mapped in the CO(2-1) radio line and the atomic component is studied through long-slit spectroscopy of the optical KI line. These observations reveal strong asymmetries in the gas distribution, which can be interpreted as a spherical envelope disrupted by a bipolar outflow.
These data, combined with other observations of this object as well as similar observations of other AGB stars, suggest that asymmetrical mass loss processes occur early during the AGB stage, well before the proto-planetary nebula phase.
Key words: stars: AGB and post-AGB stars: circumstellar matter stars: individual: o Ceti
* Based on observations carried out with the IRAM Plateau de Bure Interferometer, the Canada-France-Hawaii Telescope, and at the Haute-Provence Observatory. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).
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© European Southern Observatory (ESO) 2000
Online publication: October 30, 19100