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Reports from Geisei Observatory <October 4, 2013>


    Comet Encke has the shortest orbital period of about three years and is very popular with comet enthusiasts. This comet is moving toward perihelion, which takes place at the end of November. It has already become bright enough to be observable visually. The comet will be shining high in the eastern sky late at night and favorable observing conditions will continue.
    Have a look at the photograph below taken with Geisei's 70cm reflector. A 17th-magnitude small, sharp nucleus is visible with a bright jet erupted in the direction of its motion (left). The distance from the nucleus to the center of a bright glow is about 5". If this glow is the coma, the nucleus must be outside the coma. It is fan-shaped and I hesitate to call it a tail. It trails toward the sun.

6-minute exposure at 4:21, October 2, 2013 (J.S.T.)
70cm f/7 reflector with Nikon D700 at ISO 1250
Copyright (C) 2013 Geisei Observatory

Copyright (C) 2013 Tsutomu Seki.