Cool Stars 14 - Submitted Abstract # 187
This version created on 05 October 2006

Variable Accretion in the Interacting Mira AB System


Margarita Karovska, Harvard-Smithsonian CfA
Brian Wood, JILA

Mira AB is the nearest symbiotic system consisting of an AGB donor
(Mira A) and a compact accretor (Mira B), likely a white dwarf.  This
interacting binary, being one of the few accreting systems in which
the components are resolvable, provides a unique opportunity to study
the spectral energy distributions of the components individually, and
therefore test accretion models.  Recent ultraviolet spectra from the
HST and FUSE show that UV line and continuum fluxes observed from Mira
B are increasing back towards the levels observed by IUE in early
nineties.  From wind absorption features, we estimate that Mira B's
wind has increased in strength along with the accretion rate.
Variable mass loss from Mira A could have caused the changes in the UV
flux of Mira B observed in the past 15 years, signaling that the
system is undergoing important transformations.  These transformations
may have set the stage for the remarkable X-ray outburst from Mira A
that was observed by Chandra in 2003-2004.

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