AAO image reference AAT 117a. « Previous || Next »
Top left is NE. Image width about 55 arc min
Image and text © 2001-2010, Australian Astronomical Observatory, Photograph from AAT plates by David Malin.
The warming action of sunlight on the tiny nucleus of the comet evaporates volatile materials from its surface which expand rapidly in the vacuum of space, producing the large coma. Solar radiation pressure sweeps back this tenuous cloud into the typical comet shape, and this process begins close to the cometary nucleus. The structure shown above was extracted from the same original plates that were used for AAT 117, using an unsharp mask to reveal the hidden inner structure.
This picture was made after the comet had rounded the sun and was heading back into the cold of interstellar space. The multicoloured 'rain' is the trails of countless stars, photographed, like the comet, in red, green and blue light as the Anglo-Australian Telescope followed the comet's motion in front of the Milky Way. A deeper and wider field view was taken at about the same time by the UK Schmidt Telescope.
Related images, other comets
AAT 46. Halley's Comet, December, 1985
AAT 117. Comet Halley on April 9-10, 1986
UKS 19. Halley's Comet on 12 March, 1986
UKS 33. Comet Hyukatake, March, 1996
UKS 34. Halley's Comet on 9-10 April, 1986 (UK Schmidt image)
MISC 20. Comet Halley hanging in the Milky Way in 1986.
B&W image Features in the dust tail of Comet Halley, 12 March, 1986
For details of photographic exposure, search technical table by UKS reference number.
| emission nebulae
| reflection nebulae
| dark nebulae
| planetary nebulae
| star clusters
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