title: A collimated, high-speed outflow from the dying star V Hydrae.
abstract: Stars with masses in the range 1-8 solar masses (M(\circ)) live ordinary lives for approximately 10(9)-10(10) years, but die extraordinary deaths. First, during their death throes as asymptotic giant branch (AGB) stars they eject, over 10(4)-10(5) years, half or more of their mass in slowly expanding, spherical winds, and then, in a short (a few 100-1,000 years) and poorly understood phase, they are transformed into aspherical planetary nebula. Recent studies support the idea that high-speed, jet-like flows play a crucial role in this transformation. Evidence for such outflows is indirect, however; this phase is so short that few nearby stars are likely to be caught in the act. Here we report the discovery of a newly launched, high-speed jet-like outflow in the nearby AGB star, V Hydrae. We have detected both proper motions and ongoing evolution in the jet. These results support a model in which the jet is driven by an accretion disk around an unseen, compact companion. We also find a central, dense equatorial disk-like structure which may enable and/or enhance the formation of the accretion disk.
authors: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109, USA. raghvendra.sahai@jpl.nasa.gov
authors: R
authors: R
authors: Sahai
authors: M
authors: M
authors: Morris
authors: G R
authors: GR
authors: Knapp
authors: K
authors: K
authors: Young
authors: C
authors: C
authors: Barnbaum