Abstract:
The Changes in the Ca II K line profile of the F0 supergiant Canopus have been studied from the high dispersion coude spectrograms obtained since 1975. The emission in the core of the line is variable in a timescale of few days. Similar activity seems to be occuring in Mg II h and k lines also. This is attributed to the variability in the appearance of plage areas on the stellar surface.
