Investigation of the Differential Rotation by H-Alpha Filaments and Long-Lived Magnetic Features for Solar Activity Cycles 20 and 21

Abstract

For solar activity cycles 20 and 21 (1966-1985) the solar differential rotation has been investigated using Hα filaments and relatively small-scale long-lived magnetic features with negative and positive polarities. We used annual averaged angular velocities of quiescent Hα filaments from Hα photoheliograms of the Abastumani Astrophysical Observatory film collection and selected long-lived magnetic features from the McIntosh atlas (McIntosh, Willock, and Thompson, Atlas of Stackplots, NGDC, 1991). We have determined coefficients of Faye's formulas for Hα filaments as well as for long-lived magnetic features and have found that for solar cycles 20 and 21 the Hα filaments have lower rotation rates and rotated more differentially than the long-lived magnetic features.

15 pages,9 figures

References in corpus (4)

• Differential rotation measurement of soft X-Ray corona
• Differential coronal rotation using radio images at 17 GHz
• Angular momentum conservation and torsional oscillations in the Sun and solar-like stars
• Comparison of the sidereal angular velocity of subphotospheric layers and small bright coronal structures during the declining phase of solar cycle 23

Cited by in corpus (5)

• On the Helicity of Open Magnetic Fields
• Material supply and magnetic configuration of an active region filament
• Evolution of solar wind sources and coronal rotation driven by the cyclic variation of the Sun's large-scale magnetic field
• Accounting for Differential Rotation in Calculations of the Sun's Angular Momentum-loss Rate
• Long-term Evolution of the Solar Corona Using PROBA2 Data