The density of cometary protons upstream of comet Halley's bow shock

Journal Article · Wed Feb 01 00:00:00 EST 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA02p01261· OSTI ID:5833760

Neugebauer, M; Goldstein, B E ^[1]; Balsiger, H ^[2]; Neubauer, F M ^[3]; Schwenn, R ^[4]; Shelley, E G ^[5]

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1. California Institute of Technology, Pasadena (USA)
2. Univ. of Bern (Switzerland)
3. Univ. of Cologne (West Germany)
4. Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (West Germany)
5. Lockheed Palo Alto Research Lab., CA (USA)

Cometary protons picked up by the solar wind were detected by the high energy range spectrometer of the Giotto ion mass spectrometer starting at a cometocentric distance of {approximately}12 {times} 10{sup 6} km. On the average, the density of cometary protons varied approximately as the inverse square of the cometocentric distance, reaching a value of 0.11 cm{sup {minus}3} just outside the bow shock. The data can be successfully fit to models that include substantial amounts of both slow ({approximately}1 km/s) and fast ({ge} 8 km/s) H atoms beyond the bow shock. Large local variations in the density of picked-up protons can be explained on the basis of variations in the direction of the interplanetary magnetic field in upstream regions where pitch angle scattering was weak.

• OSTI ID: 5833760
• Journal Information: Journal of Geophysical Research; (USA), Vol. 94:A2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HALLEY COMET
SOLAR WIND
INTERACTIONS
DENSITY
DISTANCE
HYDROGEN
INTERPLANETARY MAGNETIC FIELDS
IONIZATION
PROTONS
SATELLITES
SHOCK WAVES
SPECTROMETERS
VARIATIONS
BARYONS
COMETS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HADRONS
MAGNETIC FIELDS
MEASURING INSTRUMENTS
NONMETALS
NUCLEONS
PHYSICAL PROPERTIES
SOLAR ACTIVITY
640107* - Astrophysics & Cosmology- Planetary Phenomena