Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-29T06:55:30.829Z Has data issue: false hasContentIssue false
  • English
  • Français

Spatial Distribution and Color of Dust in Halley’s Inner Coma

Published online by Cambridge University Press:  12 April 2016

J. Clairemidi ,
E. Brandon ,
P. Rousselot  and
G. Moreels
J. Clairemidi
Affiliation:
Observatoire de Besançon BP 1615 25010 Besancon CedexFrance
E. Brandon
Affiliation:
Observatoire de Besançon BP 1615 25010 Besancon CedexFrance
P. Rousselot
Affiliation:
Observatoire de Besançon BP 1615 25010 Besancon CedexFrance
G. Moreels
Affiliation:
Observatoire de Besançon BP 1615 25010 Besancon CedexFrance

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Composite images of the intensity of solar radiation scattered by dust in Halley’s coma are constructed by using the three-channel spectra obtained during the approach phase of the Vega 2 spacecraft. They cover a sector centered on the nucleus that has a radius of 40000 km and an angular extent of 50°. A radial plot of dust-scattered intensity shows that it varies as the inverse of impact parameter p where p is smaller than 3200 km or higher than 7000 km. In the intermediate 3200-7000 km distance range, the intensity varies as p−1.52. At longer distances, two jets are present with a contrast comparable to the gas jets which appear in the OH and CN images.

The color of dust shows a slight excess of near-UV radiation in a diffuse region between 10000 and 30000 km which appears to be connected with the two jets. In the region called “valley”, between the jets at distances p > 25000 km, the dust-scattered intensity shows an excess of red. The color, expressed as the ratio of intensities at 377,482 and 607 nm is interpreted in terms of Mie theory. It is suggested that the dust particles progressively differentiate. A proportionally more important population of small submicronic grains appears at p > 8000 km. This population seems to correlate with the jets.

Type
Cometary Dust: Observations and Evolution
Information
International Astronomical Union Colloquium , Volume 126: Origin and Evolution of Interplanetary Dust , 1991 , pp. 277 - 280
Copyright
Copyright © Kluwer 1991

References

A’Heam, et al. (1986). Nature 324, 649–651 Google Scholar
Clairemidi, J., Moreels, G., Krasnopolsky, V.A., (1990). Icarus, 86, 115–128 Google Scholar
Combes, et al. (1988). Icarus, 76, 404–436 Google Scholar
Eaton, N. (1984). Vistas in Astronomy >21, 111–129.21,+111–129.>Google Scholar
Eberhardt, P. et al. (1987). Astron. Astrophys. 187. 481–484 Google Scholar
Greenberg, J.M., Hage, J.I., (1990). Ap. J. 261, 1, 260–274 Google Scholar
Hoban, S., A’Hearn, M.F., Birch, P.V., Martin, R. (1989). Icarus, 79., 145–158 Google Scholar
Jessberger, E.K. et al. (1988). Nature 332, 691–695 Google Scholar
Keller, H.U. et al., (1986). Nature 321 320–326 CrossRefGoogle Scholar
Levasseur-Regourd, A. C. et al. (1986). Nature 321 341–344 Google Scholar
Levasseur-Regourd, A. C., Dumont, R., Renard, J.B., (1990). Icarus, 86, 264–272 Google Scholar
Mazets, et al. (1987). Astron. Astrophys. 187, 699–706 Google Scholar
McDonnell, J.A.M. et al. (1987). Astron. Astrophys. 187. 719–741 Google Scholar
Moreels, et al. (1987). Astron. Astrophys. 187, 551–559 Google Scholar
Mukai, T., Mukai, S., Kikuchi, S., (1987). Astron. Astrophys. 187, 650–652 Google Scholar
Nappo, S. et al., (1989). Asteroids, comets, meteors III, University Uppsala, 397–400 Google Scholar
Thomas, N., Keller, H.U. (1990). Ann. Geophys.8, 2, 147–166 Google Scholar
Sagdeev, R.Z. et al. (1986). Nature 321, 262–266 CrossRefGoogle Scholar
Suzuki, B., Kurihara, H., Watanabe, H.,(1990), Publ. Astr. Soc. Japan (Letters), submittedGoogle Scholar