A NEW ANALYSIS OF THE BUTTERFLY DIAGRAM FOR SOLAR FILAMENTS

In this article we study the filament cycle on butterfly diagrams for each type of filament defined according to the Tandberg-Hanssen classification, which is based on the magnetic polarities of the unipolar magnetic regions adjacent to the filaments. It distinguishes between type A filaments, which are located on the same line of magnetic field reversal as the active regions, from the type B filaments that are not. A more in-depth analysis has led us to subdivide type A filaments into active region filaments (Aa), quiescent filaments (Aq) and polar filaments (Ap). Type B filaments are the classical quiescent filaments (Bq). We have developed butterfly diagrams for the Aq and Ap filaments together, and separately for the Aa, and lastly for the Bq. Analyzing their time variation, we can see that their full cycle is of 22-yr duration, made up of two 11-yr periods, in which the type B filaments of the first: 11-yr become the type A (all three types) of the following 11-yr, considering that the active regions are emerging now on these magnetic field polarity reversal lines.