(Sub)stellar companions shape the winds of evolved stars
  Binary interactions dominate the evolution of massive stars, but their role
is less clear for low- and intermediate-mass stars. The evolution of a
spherical wind from an asymptotic giant branch (AGB) star into a nonspherical
planetary nebula (PN) could be due to binary interactions. We observed a sample
of AGB stars with the Atacama Large Millimeter/submillimeter Array (ALMA) and
found that their winds exhibit distinct nonspherical geometries with
morphological similarities to planetary nebulae (PNe). We infer that the same
physics shapes both AGB winds and PNe; additionally, the morphology and AGB
mass-loss rate are correlated. These characteristics can be explained by binary
interaction. We propose an evolutionary scenario for AGB morphologies that is
consistent with observed phenomena in AGB stars and PNe.
