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Reports from Geisei Observatory <April 23, 2006>

Nucleus B of 73P/Schwassmann-Wachmann 3 begins to break up.

    There were many clouds during the daytime on April 23. But the sky began to clear up in the evening and I hurriedly went to the observatory. Over a period of about 3 hours I observed Comet Schwassmann-Wachmann 3 and others.
    Nucleus C, the brightest of all, was at 8th magnitude and barely visible through 7x50 binoculars. I think there is a great possibility that this will not become a naked-eye object. What do you think? However, the tail seems to have grown quite well.
    Nucleus B has become very diffuse and begun to break up into two or more fragments. Refer to the photograph taken on April 21 at Geisei Observatory. In the photograph the nucleus is narrow and extended into the direction of its motion , but there is no sign of breaking up.
    In the close-up image taken on April 23, the nucleus is clearly split. It is certain that this occurred within the past two days. I measured these two nuclei.
    Is the first nucleus original Nucleus B itself?
73P-B/Schwassmann-Wachmann 3
(the lading nucleus)

2006UT        RA (2000.0)   Decl.         m2
Apr.23.59792  15 19 33.60  +29 58 56.6   13.8    372
    23.60034  15 19 34.17  +29 59 02.0           372

(the following nucleus)
Apr.23.59792  15 19 33.02  +29 58 46.8   14.2    372
    23.60034  15 19 33.48  +29 58 52.9           372
    As they appear stellar, the accuracy of measurement is not bad. The leading nucleus is very clear and shining intensely. I wonder if this is Nucleus B itself. Although the nucleus is faint, the total magnitude is 8.9. It is hazy and extends like fog.
    Past midnight, the sky became hazy as if covered by fog. Was it dust haze again from the "yellow sand dust", which was blown over from the deserts of China and Mongolia? The comet disappeared into a night fog of yellow dust.

73P-B/Schwassmann-Wachmann 3
2-minute exposure from 23.:20, April 23, 2006 (J.S.T.)
60cm f/3.5 reflector, TMY 400 film

Copyright (C) 2006 Tsutomu Seki.