ENERGY RELEASE FROM A LARGE-SCALE MAGNETIC NULL POINT IN THE CORONA?

摘要

We observed how a flare disturbes a system of interconnecting loops between neighboring active regions. The disturbed loops brighten in SOHO/EIT images of the coronal magnetoplasma. They are part of a large scale structure embracing a weak field range in the photospheric and coronal magnetic field. Near the weak field site but away from active regions and from the EIT-detected loop heating, an initially narrowband nonthermal meter wave radio source is observed by the AIP spectrometer and the Nancay radio heliograph. The formation of this source and the EIT loop brightening can be consequences of current sheet activation and excessive coronal heating at a disturbed magnetic null point.