Observation of a ~ 7 MeV Electron Super-flux at 5 AU by Ulysses
Abstract
From the Ulysses launch up to the end of 1995, the 4-10 MeV energy electron count rate of the COSPIN/KET instrument has been consistent with simple expectations from Jovian electrons propagation. From the beginning of 1996 to the end of 1998, Ulysses was below ~ 30 degrees of heliographic latitude and between 4.5 and 5.4 AUs from the Sun, making it the first spacecraft to reach the region around the Jupiter orbit but with the planet being very far away. During this period, this electron flux around 7 MeV has surprisingly increased and has stayed at a high level up to the latest data of early 1999. In this paper, we present these data and discuss the possible origin of this electron super-flux, which reaches a level similar to that obtained in 1991 when Ulysses was perfectly magnetically connected to Jupiter.
- Publication:
-
26th International Cosmic Ray Conference (ICRC26), Volume 7
- Pub Date:
- 1999
- Bibcode:
- 1999ICRC....7..135F