The new regimes of milli-arcsecond imaging parameter space depicted in
Figure 1.19 open up a wealth of phenomena in stellar
astrophysics that have as yet only been revealed as point sources of
radio emission. Imaging with linear resolution of 
1 AU will be
possible out to distances above a kpc. As noted in the previous
section, this dimension is characteristic of the radii of red giant
stars. This dimension is also typical of the binary separation of
semi-detached interacting binary systems containing giant stars, such
as symbiotic stars, the winds of Wolf-Rayet, OB and Be stars,
planetary nebulae, and the very early stages of novae outbursts. At
current resolving power, imaging investigations of these types of
objects are constrained to examination of material that has propagated
to large distances from the point of origin before becoming
resolved. The SKA will finally allow imaging of thermal radio
emission on the scale of the phenomena that give rise to these
sources. The circumstellar disks of Be stars can be imaged out to
several hundred pc; red giant photospheres are resolvable out to more
than a kpc; the binary separation of `D' type symbiotic stars, the
first week of nova ejecta evolution, and the winds of WR and OB stars
can be resolved to several kpc.