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Reports from Geisei Observatory <February 27, 2006>

73P/Schwassmann-Wachmann 3 (C) and C/2006 A1 (Pojmanski)

    February 27 turned into a perfect clear day. I wondered if this might be the last clear day of this winter. As usual, I began observing with the 60cm reflector before midnight and persisted until 5.30 in the morning.

    Nucleus C of 73P/Schwassmann-Wachmann brightened greatly to become just visible in the 20cm refractor at 60x. It could be around 12.5 magnitude estimating from the telescope's limiting magnitude, though without suitable comparison stars its exact magnitude was not clear. In the photograph below the comet seems to be trailing a magnificent 30'-long tail. An unexpectedly bright object, possibly nucleus B, is seen in the photograph and I am trying to check its identity. Its 3'-long tail is so impressive that it could be easily mistaken for nucleus C one month ago. As you can see, an advantage of photography over CCDs is a wider field it can cover.

    By the way, the biggest surprise of the day was C/2006 A1 (Pojmanski) becoming visible low in the dawn sky. I was mesmerized by its breathtaking view when it moved into the center of the field of the 20cm telescope. The coma was very bright at 4.5 magnitude and its magnificent tail was over 1 degree long.

    If you encountered a comet like this one while sweeping the sky, you would be stunned. Your hand drawing the comet would be shaking with tension and excitement, even if you were an experienced observer. If you are not sure whether the object you have discovered is a comet or just a nebula, usually it will not turn out to be a comet. When you have discovered a real comet, you will know it by a strong emotion rising inside you.

    Unfortunately, with the encroaching twilight, the detail of the comet was overwhelmed by morning glow. The photograph shown below is the first of a series of photos I have taken. It shows a large coma (5' in size) even though it was a one-minute exposure. Errors in positional measurements will be within +/- 2". For measurements, I will use the fourth one of the four photos I have taken.

73P/Schwassmann-Wachmann 3 (nucleus C)
21-minute exposure from 1:07, February 28, 2006 8(J.S.T.)
60cm reflector, TM400 film

C/2006 A1 (Pojmanski)
4-minute exposure from 5:19, February 28, 2006 (J.S.T.)
60cm reflector, TM400 film

Copyright (C) 2006 Tsutomu Seki.