This textbook is intended as an introduction to the physics of solar and
stellar coronae, emphasizing kinetic plasma processes. It is addressed
to observational astronomers, graduate students, and advanced
undergraduates without a back- ground in plasma physics. Coronal physics
is today a vast field with many different aims and goals. Sort- ing out
the really important aspects of an observed phenomenon and using the
physics best suited for the case is a formidable problem. There are
already several excellent books, oriented toward the interests of
astrophysicists, that deal with the magnetohydrodynamics of stellar
atmospheres, radiation transport, and radiation theory. In kinetic
processes, the different particle velocities play an important role.
This is the case when particle collisions can be neglected, for example
in very brief phenomena - such as one period of a high-frequency wave -
or in effects produced by energetic particles with very long collision
times. Some of the most persistent problems of solar physics, like
coronal heating, shock waves, flare energy release, and particle
acceleration, are likely to be at least partially related to such pro-
cesses. Study of the Sun is not regarded here as an end in itself, but
as the source of information for more general stellar applications. Our
understanding of stellar processes relies heavily, in turn, on our
understanding of solar processes. Thus an introduction to what is
happening in hot, dilute coronae necessarily starts with the plasma
physics of our nearest star.