The Comet seen from Portugal

 All images (except April 4) were taken with the CCD-Camera from the balkony of my hotel room which had a view to the north. This made it possible to obtain the images without setting up the whole mount day by day but according to the light of the village (Falesia, abt. 10km east of Albufeira) we had problems to record the plasma tail on our wide angle images (the background light was too much and the camera's sensitivity for blue light is too low).

 Each images shown here consists of two views. Mostly the 1m image is shown together with a wide angle image. The top line alway shows a logarithmically scaled version of the image. In case of 1m or 2m focal length the bottom line shows a shift differenced image (it is computed in the same way as described on the rotational shift page) except that instead of a rotation the subtracted images were only shifted 3 pixel up and down. - That was the original work I did when I returned from Portugal. But in the meantime I had some more time to try rotational shift differencing on these images again. When the rotation angle is more than 15 degrees this message suddenly shows the shell structure as well. Although this definitly is not the best way to process the images as some jets create dark and light areas whithin the shells, I still put the rotated images onto the tabloids. I used an angle of 20 degrees. On the wide angle images the shift method has been applied as described on an extra page. The angle was here 7 degrees.

  March 27, 1997  March 28, 1997  March 29, 1997
March 30, 1997  March 31, 1997  April 4, 1997The wide angle image from March 31 shows a gradient within the background which was caused by a fire abt. 3 km from the hotel. The smoke was rising into the sky and lit by the lamps from the village. The image from April 4 was taken from the COAA in Portugal, a "holiday observatory" where accomodation is given and telescopes are provided for the visitors. The COAA is present in the internet as well (I will provide the address here as soon as it is available).

Back home

On the wide angle image of April 4 a tree within my garden wanted to show his presence. But still the gas tail can be seen quite well as the night was extremely clear. The new moon was not yet desturbing the sight. Two days later the moon was that bright again, that the gas tail is almost invisible to the ccd camera. The image shows a nice gradient in the background brightness which was caused by the moonlight.

 On April 23 I had the last chance to obtain an image of the comet. Only a closeup of the comet's nucleus was made because the comet was too close to the horizon to do any more images than this last glimpse as it disapperead behind bushes close to my observatory. Still some detail can be seen.

  April 9, 1997  April 11, 1997  April 23, 1997