  We combine the catalogue of eclipsing binaries from the All Sky Automated
Survey (ASAS) with the ROSAT All Sky Survey (RASS). The combination results in
836 eclipsing binaries that display coronal activity and is the largest sample
of active binary stars assembled to date. By using the (V-I) colors of the ASAS
eclipsing binary catalogue, we are able to determine the distances and thus
bolometric luminosities for the majority of eclipsing binaries that display
significant stellar activity. A typical value for the ratio of soft X-ray to
bolometric luminosity is L_X/L_bol ~ a few x 10^-4, similar to the ratio of
soft X-ray to bolometric flux F_X/F_bol in the most active regions of the Sun.
Unlike rapidly rotating isolated late-type dwarfs -- stars with significant
outer convection zones -- a tight correlation between Rossby number and
activity of eclipsing binaries is absent. We find evidence for the saturation
effect and marginal evidence for the so-called "super-saturation" phenomena.
Our work shows that wide-field stellar variability searches can produce a high
yield of binary stars with strong coronal activity.
  The combined ASAS and RASS catalogue, as well as the results of this work are
available for download in a form of a file.

Astrophysics