Variability of comet Halley's coma: VEGA-1 and VEGA-2 magnetic field observations.
Abstract
The differences of the VEGA-1 and VEGA-2 magnetic field investigations near Comet Halley are discussed. The different draping structures of the magnetic field observed by VEGA-1 and VEGA-2 are caused by variations of the solar wind parameters and of the cometary activity during this period. The magnetic field reversal region observed only during the closest approach of VEGA-1 is correlated with high energetic particle streams and ground-based observations of a disconnection event. A broad minimum of the wave activity during the inbound phase of both encounters occurs in the same region where a substantial change of the slope of the total magnetic field and of the plasma velocity takes place and where the observed neutral gas density has a discontinuity. The VEGA-1 and -2 magnetic field observations are compared with the results of 3-D MHD computer simulations. It is concluded that most of the measured variability is the result of IMF variations.
- Publication:
-
Diversity and Similarity of Comets
- Pub Date:
- September 1987
- Bibcode:
- 1987ESASP.278...63S
- Keywords:
-
- Cometary Atmospheres;
- Halley'S Comet;
- Interplanetary Magnetic Fields;
- Plasma Diagnostics;
- Vega Project;
- Computerized Simulation;
- Discontinuity;
- Magnetic Field Configurations;
- Solar Wind;
- Lunar and Planetary Exploration;
- Comet 1986 III Halley;
- Cometary Comae:Structure