Coronal astronomy is by now a fairly mature discipline, with a quarter
century having gone by since the detection of the first stellar X-ray coronal
source (Capella), and having benefitted from a series of major orbiting
observing facilities. Several observational characteristics of coronal X-ray
and EUV emission have been solidly established through extensive observations,
and are by now common, almost text-book, knowledge. At the same time the
implications of coronal astronomy for broader astrophysical questions (e.g.
Galactic structure, stellar formation, stellar structure, etc.) have become
appreciated. The interpretation of stellar coronal properties is however still
often open to debate, and will need qualitatively new observational data to
book further progress. In the present review we try to recapitulate our view on
the status of the field at the beginning of a new era, in which the high
sensitivity and the high spectral resolution provided by Chandra and XMM-Newton
will address new questions which were not accessible before.Comment: Space Science Reviews, in press, 132 pages (full paper available at
ftp://astro.esa.int/pub/ffavata/Papers/ssr-preprint.pdf
