ENERGETIC ELECTRONS FROM THE CORONA OF A QUIESCENT SUN

摘要

On 5 May, 1998 several arnisotropic bursts of energetic (38―100 keV) electrons were observed by the Electron, Proton and Alpha Monitor (EPAM) on the Advanced Composition Explorer (ACE) spacecraft. At the time, solar activity was low with no large flares, neither is there evidence to suggest acceleration at an interplanetary shock. However, the observations show these electron bursts share characteristics with coronal flare electron events. Such events are often seen whilst the Sun is quiescent, at electron energies typically below ～15 keV. Evidence is presented which suggests the electrons from 5 May, like coronal flare electrons, were accelerated and released from the high corona, a few solar radii from the solar surface.