3-D Dynamics of Interactions between Stellar Winds and the Interstellar
  Medium as Seen by AKARI and Spitzer
  Recent far-infrared mapping of mass-losing stars by the AKARI Infrared
Astronomy Satellite and Spitzer Space Telescope have suggested that
far-infrared bow shock structures are probably ubiquitous around these
mass-losing stars, especially when these stars have high proper motion. Higher
spatial resolution data of such far-infrared bow shocks now allow detailed
fitting to yield the orientation of the bow shock cone with respect to the
heliocentric space motion vector of the central star, using the analytical
solution for these bow shocks under the assumption of momentum conservation
across a physically thin interface between the stellar winds and interstellar
medium (ISM). This fitting analysis of the observed bow shock structure would
enable determination of the ambient ISM flow vector, founding a new technique
to probe the 3-D ISM dynamics that are local to these interacting systems. In
this review, we will demonstrate this new technique for three particular cases,
Betelgeuse, R Hydrae, and R Cassiopeiae.
