The Butterfly Diagram Internal Structure

Eclipse on the Coral Sea: Cycle 24 Ascending

物理学;天文学

Ternullo, Maurizio^1

INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania, Italy^1

关键词: Activity streams;    Butterfly diagrams;    Butterfly wings;    Higher latitudes;    Internal structure;    Semi-cycles;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/440/1/012021/pdf
DOI  :  10.1088/1742-6596/440/1/012021

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

A time-latitude diagram, where the spotgroup area is taken into account, is presented for cycles 12 through 23. The results show that the spotted area is concentrated in few, small portions ("knots") of the Butterfly Diagram (BD). The BD may be described as a cluster of knots. Knots are distributed in the butterfly wings in a seemingly randomly way. A knot may appear at either lower or higher latitudes than previous ones, in spite of the prevalent tendency to appear at lower and lower latitudes. Accordingly, the spotted area centroid, far from continuously drifting equatorward, drifts poleward or remains stationary in any hemisphere for significant fractions (= 1/3) of the cycle total duration. In a relevant number of semicycles, knots seem to form two roughly parallel, oblique "chains", separated by an underspotted band. This picture suggests that two (or more) "activity streams" approach the equator at a rate higher than the spot zone as a whole.