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Reports from Geisei Observatory <August 19, 2011>


Comet Crommelin is back

    27P/Crommelin, which has returned many times with a 28-year period, was discovered by Mr. Masamitsu Yamasaki as far back as in 1928. Dr. Crommelin of the British Astronomical Association studied this periodic comet, which had returned many times in the past, and the comet was named Crommelin. Twenty-eight years later, at apparition of October 1956, Seki rediscovered this comet in Kochi, the first in Japan. It was found 10 degrees north of the position predicted by the British Astronomical Association. Another 28 years later, in 1984, photographic observations were made with the 60cm reflector at the newly established Geisei Observatory.
    In the predawn sky of May 13, 2011, Geisei observed this comet, the earliest observation for this year's apparition. I am fond of this comet, as I have observed it at three apparitions. This year, the comet has appeared in twilight skies close to the sun, which makes the observation difficult.
    This photograph was made with a Nikon D700. Mr. Shigeo Shimomoto has image-processed two frames to create this beautiful photo


27P/Crommelin
A composite of two images: a 3-minute-exposure at 3:28 and a 5-minute exposure at 3:32, July 11, 2011
Copyright (C) 2011 Geisei Observatory





Copyright (C) 2011 Tsutomu Seki.