Brunstein Observatory

Kreiensen, Germany

Comet Hyakutake


Attention: The images might not be correctly displayed on some computer displays not using 24 bit color modes. In that case please save the image and take a look at them with other software than your web browser (e.g. xv by John Bradley)...

 The left part of the images are saled logarithmically. No other image processing has been done there. The right parts show the comet after the rotational shift differencing method has been applied. For more detail on these image processing methods please refor to the extra pages... 


During 1996 Hyakutake's comet was a very bright object. The following five images of the comet show, how the coma and the tail region of the comet have changed during its journey across the northern sky.

 The first image was taken on March 25. At this day we (Stefan Schwarzer) and me took my CCD camera, my 5 inch reflector and drove into the nearby Harz mountains to get out of the Leine Valley which was again trying to stop us from observing by producing a lot of mist. Our decision turned out to be a good idea. The image (as all the others as well) have been taken using the Track and Accumulate mode of the CCDOPS software. In this mode the first image is downloaded from the camera. Then a guide star (this the the comets nucleus) is selected and the software automatically adds as many images as set directly in the camera. After the last image has been taken, the "unused" pixels are removed from the image and the resulting image is downloaded. Of course dark frame substraction is done for each image. This time 15 images of 1.25 seconds each have been added.

 

 Two days later I had the chance to get an image of the comet from my garden. At this time the observatory was well planned but construction had not started, so only really good nights could be used for observation, as each time the telescope, the camera and the computer had to be transported and it took some time to set up the equipment. This time the speed of the comet was clearly visible in front of the fixed starts. During the time the images were taken the comet speeded forward so the stars left a nice trail on the image. The gap in the star trails stems from the download of the first image to select a guide star (see above). This time only 6 images of 1.25 seconds each were added.

 

 Another three days had passed until the next image could be aquired. The Comet had changed again. It became less bright so that now 10 exposures of 2 seconds were added to get this image. The rotated image does not look too spectacular and I almost wanted to stop rotating Hyakutake's comet...

 

 But then after the perihelion this image came out of my camera. The look of Hyakutake's comet had now dramatacially changed. The beginning of the tail was much brighter so that even close to the center three stong streamers can be seen. These streamers are shown with extreme contrast in the rotated image. Although the comet lost a lot of its brightness so that 4 exposures of 10 seconds each had to be added for this image, it now looked really impressive...

 

 This actually was the last image I could take of the comet as it now hurried down to the horizon. On the next evening it was already behind a tree when I finished setting up my equipment. So lets just enjoy this last farewell of Hyakutake's comet to the Brunstein Observatory...

 

 


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