Astron. Astrophys. 324, 713-716 (1997)

Vertical current and flare sites in an active region in 1989 October

Hongqi Zhang

Beijing Astronomical Observatory, Chinese Academy of Sciences Beijing 100080, China

Received 19 September 1996 / Accepted 6 March 1997

Abstract

We study the configuration of the vector magnetic field in a -active region in October 1989. The distribution of the foot points of the electric current loops can be confirmed by the photospheric vertical current, which is inferred by the observational photospheric vector magnetograms resolved -ambiguity of the transverse components. The distribution of the photospheric electric current can be separated by several kinds of simple structures in the active region. The formation of new electric current in the photosphere is caused by the emergence of a magnetic flux or is related with the magnetic shear and squeeze. In the electric current picture, the flares are probably caused by the interaction of different electric current loops.

Key words: Sun: flares Sun: magnetic fields

Contents

• 1. Introduction
• 2. Magnetic shear
• 3. Electrical current and flares
  • 3.1. Photospheric vertical electrical current
  • 3.2. Basic form of electric current
  • 3.3. Combination of electric current
  • 3.4. Electrical current and flares
• Acknowledgements
• References

© European Southern Observatory (ESO) 1997

Online publication: May 26, 1998

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