The Hydrogen Coma of Comet Halley Before Perihelion: Preliminary Observations with Dynamics Explorer 1

  1. Thomas J. Birmingham and
  2. Alexander J. Dessler
  1. J.D. Craven,
  2. L.A. Frank,
  3. R.L. Rairden and
  4. M.R. Dvorsky

Published Online: 19 MAR 2013

DOI: 10.1029/SP027p0305

Comet Encounters

Comet Encounters

How to Cite

Craven, J.D., Frank, L.A., Rairden, R.L. and Dvorsky, M.R. (1988) The Hydrogen Coma of Comet Halley Before Perihelion: Preliminary Observations with Dynamics Explorer 1, in Comet Encounters (eds T. J. Birmingham and A. J. Dessler), American Geophysical Union, Washington, D.C.. doi: 10.1029/SP027p0305

Author Information

  1. Department of Physics and Astronomy, the University of Iowa, Iowa City, Iowa 52242

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875902395

Online ISBN: 9781118668757

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Keywords:

  • Comet Halley;
  • Hydrogen coma;
  • Photometer's scan;
  • Solar Lyman radiation;
  • Vacuum-ultraviolet (VUV)

Summary

The hydrogen coma of Comet Halley has been observed in resonantly scattered solar Lyman-α radiation during the period 1–29 January 1986 as the comet approached perihelion. These observations were obtained with the imaging photometer for vacuum-ultraviolet wavelengths on the spacecraft Dynamics Explorer 1. For the initial analysis of observations available in 17 orbits distributed throughout the period, least-squares fits are computed for the observed exponential decrease in brightness with radial distance from the nucleus. Brightness at the nucleus increased from ∼3 to 17 kR during the observing period. Preliminary analysis yields water production rates of ∼3.6×1029 and 1.9×1030 molecules/sec on 1 and 29 January, respectively.