Spectroheliograms and disk-integrated flux monitoring in the strong resonance line of Ca ii (K line) provide the longest record of chromospheric magnetic plages. We compare recent reductions of the Ca ii K spectroheliograms ...

Using the data on sunspot groups during the period 1879-2004, we have found that the solar equatorial rotation rate during the odd-numbered sunspot cycles is well correlated with the equatorial rotation rate of the preceding ...

We have used the daily values of the equatorial rotation rate determined from the Mt. Wilson daily Doppler-velocity measurements during the period 3 December 1985 – 5 March 2007 to search for periodicities in the solar ...