The wind of W Hya as seen by Herschel - I. The CO envelope
The wind of W Hya as seen by Herschel - I. The CO envelope
Asymptotic giant branch (AGB) stars lose their envelopes by means of a stellar wind whose driving mechanism is not understood well. Characterizing the composition and thermal and dynamical structure of the outflow provides constraints that are essential for understanding AGB evolution, including the rate of mass loss and isotopic ratios. …