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Reports from Geisei Observatory<August 3, 2000>

• C/1999 S4(LINEAR) Disappearing?
On August 3, we had an autumn-like clear sky late at night, as a typhoon has moved out north and a Pacific high pressure system moved in. Arriving at the observatory in the evening, I realized that tonight's observation would have to be given up with the presence of clouds and a crescent moon near where LINIEAR was supposed to be. As I peeked into the telescope, I couldn't find the disintegrated comet at the predicted position. But I seemed to be seeing a very faint image of the comet among the faint background stars. Taking into account various unfavorable conditions, I concluded it was at 10.5 (m1).

The comet was far fainter and smaller than on August 1 and the region around the coma was only one and a half times brighter than the comet's total brightness including the tail. It will survive only a few more days. The comet which left the far-away Oort Cloud has dissipated near the sun!

C/1999 S4(LINEAR)
21.51 on August 3, 2000
2-minute exposure on TM400 film
Developed by D-19 (high-contrast developer)
60cm reflector at Geisei Observatory
The original image was treated by image processing computer software.

Copyright (C) 2000 Tsutomu Seki.