Halley's Comet from Suisei

The Japanese spacecraft Suisei carried a small ultraviolet camera, known as the Ultraviolet Imager (UVI).  UVI carried a small CCD (122x153 pixels!) and imaged the

comet in the Lyman Alpha band with a field of view two and a half degrees wide.  The images were transmitted at a rate of 64 bits per second, the best Suisei could do

from interplanetary distances, and were used to observe the comet's hydrogen cloud.  Due to the fact that relatively long exposures would have been required and Suisei was

spin-stabilized, an image intensifier was used, which cut exposure times but led to the very noisy appearance of the images.  Because of the low spatial resolution of UVI and

the relatively distant flyby it made (152,000 km on March 8, 1986), the most interesting results came from its ability to monitor the comet over a long period of time,

allowing several outbursts to be observed. 

The above images, from December 11, 1985, and December 12, 1985, respectively, show a good example of a "before" and "during" view of an outburst.

This set shows a large outburst, before (February 25, 1986) and during (February 28, 1986).  At this point, the spacecraft was much closer to  the comet,

resulting in the brighter appearance.

This sequence, taken after closest approach, shows a sequence of three hourly shots of an evolving outburst that occurred on March 18, 1986.  The fourth shot

was taken on March 19, when the outburst had ended.

The final images is a stacked view of the hydrogen cloud of Halley's comet made using the March 18 images.  I am not sure if the bright spots are stars or part of the

comet (in the case of the central ones).

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Use of these images requires permission of the author.                   tedstryk@gmail.com

© Ted Stryk 2007