The Morphology of Flare Phenomena, Magnetic Fields, and Electric Currents in Active Regions. II. NOAA Active Region 5747 (1989 October)
Abstract
The paper describes October 1989 observations in NOAA Active Region 5747 of the morphology of energetic electron precipitation and high-pressure coronal flare plasmas of three flares and their relation to the vector magnetic field and vertical electric currents. The H-alpha spectroheliograms were coaligned with the vector magnetograms using continuum images of sunspots, enabling positional accuracy of a few arcsec. It was found that, during the gradual phase, the regions of the H-alpha flare that show the effects of enhanced pressure in the overlying corona often encompass extrema of the vertical current density, consistent with earlier work showing a close relationship between H-alpha emission and line-of-sight currents. The data are also consistent with the overall morphology and evolution described by erupting-filament models such as those of Kopp and Pneuman (1976) and Sturrock (1989).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1993
- DOI:
- 10.1086/172837
- Bibcode:
- 1993ApJ...411..370L
- Keywords:
-
- Electric Current;
- Electron Precipitation;
- Magnetohydrodynamics;
- Morphology;
- Solar Activity;
- Solar Flares;
- Solar Magnetic Field;
- Energetic Particles;
- H Alpha Line;
- Imaging Spectrometers;
- Photosphere;
- Solar Corona;
- Solar Physics;
- MAGNETOHYDRODYNAMICS: MHD;
- SUN: ACTIVITY;
- SUN: FLARES