Activity cycle of polar faculae

Abstract

The data of the polar faculae observed by the National Astronomical Observatory of Japan from the year 1951 through 1991 and the Mount Wilson Observatory from 1906 to 1990 were analysed. We found that the polar facula cycle is in complete antiphase with the sunspot cycle, and highly correlated with the sunspot cycle with a time shift of 51 months into the following sunspot cycle. We also made a quantitative analysis of the hemispheric distribution of polar faculae, and found that hemispheric asymmetry exists, as in solar activity at low latitude. However, the hemispheric asymmetry of polar faculae seems to have little relationship with the asymmetry of solar activity at low latitude.