Permanent and Nonstationary Plasma Phenomena in Comet Halley's Head
- Alan Johnstone
Published Online: 26 MAR 2013
Copyright 1991 by the American Geophysical Union.
Cometary Plasma Processes
How to Cite
Gringauz, K. I. and Verigin, M. I. (1991) Permanent and Nonstationary Plasma Phenomena in Comet Halley's Head, in Cometary Plasma Processes (ed A. Johnstone), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM061p0107
- Published Online: 26 MAR 2013
- Published Print: 1 JAN 1991
Print ISBN: 9780875900278
Online ISBN: 9781118663660
- Space plasmas;
The characteristics of various plasma phenomena observed near comet Halley in 1986 are studied to determine whether or not they are permanent features of the comet. Taking as the criteria for permanence that they should be observed by all spacecraft or be physically explicable, the permanent features include the near-cometary bow shock, the cometosheath, with its unique energy distribution of ions, the systematic cooling of electrons in this region, the cometopause, and the tangential discontinuity near the cometary nucleus. Among nonstationary events observed there are the unusual burst of ions with energies 100–1000 eV recorded in a direction from the Sun in the region of cometary ions at r ∼ (1–2)×104 km, the magnetic field pile-up boundary (in the region of the cometopause), the mystery region, and the precipitation of energetic electrons with ∼1 keV at r ∼ (1.5–2.5)×103 km.