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

Journal Article · Wed Feb 01 04:00:00 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), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A2; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

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