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   73003
   We propose to observe the F-type supergiant Canopus in order to
   continue a series of previous observations with various X-ray
   observatories. We hope to clarify the question whether the X-ray
   emision is variable or not, which would be a crucial point for
   unveiling the X-ray emitting mechanism (coronae or stellar winds) of
   such stars at the onset of outer convection zones. Additional
   observations of the gap-stars Capella and 24 UMa should reveal evidence
   for (non-)variablility of these stars, of which their X-ray properties
   show some similarities to the F-type supergiants, especially concerning
   the range of X-ray luminosity and variability.
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