IAU Colloquium #137, "Inside the Stars"

Asteroseismology: The Impact of Solar Space Observations

H.S. Hudson

Observations from space relevant to solar global properties (oscillations,
magnetic activity, etc) are helpful both scientifically and technically
in preparing for stellar observations.
This paper summarizes the results from the main previous
experiments (ACRIM, SOUP, and IPHIR), and also give
an initial technical report from the SXT instrument on board Yohkoh,
launched in August 1991.
The solar observations to date demonstrate the existence of several
mechanisms for low--level variability: spots, faculae, the photospheric
network, granulation, and p--mode oscillations.
The observations of oscillations have been particularly helpful in setting
limits on solar interior rotation.
In addition to the solar processes, stars of other types may have different
mechanisms of variability. These may include the
analogues of coronal holes or solar flares, modes of oscillation not
detected in the Sun, collisions with small bodies, duplicity, and
probably mechanisms not invented yet but related in interesting ways to
stellar convection and magnetism.