2004ApJ...616L..43H

Using the partially completed Submillimeter Array with five antennas, we have observed the CO J=2-1 and 3-2 emission from the envelope surrounding the carbon star V Hya. The high angular resolution (2"-4") maps show that V Hya is powering a bipolar molecular jet with an extreme velocity of 70-185 km/s. The axis of this high-velocity jet is perpendicular to the major axis of the flattened disklike envelope, which is expanding with a velocity of ∼16 km/s. There is a third kinematic component, a medium-velocity wind with a deprojected velocity of 40-120 km/s moving along the disk plane. Both the high-velocity jet and the medium-velocity wind have a dynamical timescale of a few hundred years. The flattened structure and the collimated jet observed in V Hya suggest that the formation of asymmetrical structure proceeds while the central star is still in the asymptotic giant branch phase.