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C/1996 B2 (Hyakutake)

Date:27.3.1996 Time:02:56 UT Exposure:3 x 120s
Field of View: 41o x 7o Receiver: 20482 CCD Filter:Schott RG645
Instrument: f=100mm, 1/2.8 Observatory: Hoher List Observer:T. Credner

© Copyright by the observers

Astronomical Institutes of the University of Bonn

A mosaic of three exposures is shown, which provides an Ion-tail with 41 degrees length. For a real flat sky and a higher contrast an unsharp mask was subtracted. Thats the reason for the dark parts at the comets head.

But these obvious parallel bands, starting at the end of the dust-tail, are also in the original frame. It is not really sure yet, if this is just CCD-fringing, clouds or any other non-astronomical effect. This could be the so called striae, synchronic bands that were also reported for comet West 1976 VI and comet Mrkos 1957 V on wide-field images.

If you made or just have seen equivalent images of Hyakutake, please contact me ( Especially wide-field observations of this time are object of interest.

The Instrument:

The DWARF (Deep sensing Wide Angle Recording Facility).
For the purpose of widefield imaging of cometary tail structures, a nitrogen cooled CCD-Camera with 2048 x 2048 Pixels was used. It was developed and buildt by the CCD-Group of the Astronomische Institute Bonn (Klaus Reif: Vier Millionen Bildelemente, SuW 31, 300 [3/1992]). Sometimes used for the 1.23m-telescope at Calar Alto, now the imaging optics was a small f=100mm f/2.0 Zeiss Planar camera lens. With this optics and the 3 x 3 cm2 sized chip a large field of 17 x 17 degree2 can be covered. See also the DWARF page.

  • The poster at the 1997 meeting of the Astronomische Gesellschaft in Innsbruck.