Hale-Bopp in Osnabrück

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Hale-Bopp and observatory

Hale-Bopp at the Observatory on Oldendorfer Berg

Observations taken with the telescope at the observatory of the Naturwissenschaftlicher Verein Osnabrück on Oldendorfer Berg near Melle. The telescope has 60 cm aperture and a focal length of 7,46 m, we used a SBIG ST-6 CCD camera with a field of 3'x 4'.
observer: Erwin Heiser et al., eheiser@os-net.de
image processing: E. Heiser und A. Hänel

Wide angle exposures

Conventional photos taken with various focal lengths (f=55mm and mainly f=200mm) on different slide and negative emulsions (therefore different colour hues). Paper prints were scanned, digitized and the further processed.
Photos and image processing: Andreas Hänel u. a., ahaenel@rz.uni-osnabrueck.de

Observatory and Hale-Bopp on the 1997-21-03, with fixed camera, exposed for ca. 15s. The observatory was illuminated by the moon.

Animation

of the changes in the comets head between Sept. 8th, 1996, und May 2nd, 1997

For this animation we selected those of the following exposures that have been treated with the rotation radial-shift algorithmus.
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    1996-05-09

    Hale-Bopp 5.9.
    5 jets emanate from the nucleus.


    1996-08-09

    Hale-Bopp 8.9.
    original, exp. 30 s, without filter
    Hale-Bopp rot.
    rotation radial-shift algorithm.
    Hale-Bopp unsharp masking
    unsharp masking (SIGMA=4 pixels).

    Animations

    from exposures between UT 21:19:25 and UT 22:53:53. Video processing: S. Hügelmeyer, A. Hänel.

    1996-15-09

    Hale-Bopp original
    original, exp. 30s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1996-06-10

    Hale-Bopp original
    original, exp. 30s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-02-02

    Wide angle 2.2.
    f=55mm/1:1.8, Fujichrome 400, 15s with fixed camera, Georgsmarienhütte/Holzhausen, A. Hänel
    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=3 Pixel).

    More informations: ESO-Hale-Bopp-Page and Observatoire du Pic du Midi.

    1997-04-03

    Wide angle 4.3.
    f=55mm/1:1.8, Fujichrome 400, exp. ca. 40s with fixed camera, Georgsmarienhütte/Holzhausen, A. Hänel
    Hale-Bopp original
    original, exp. 1s, without filter, with Shapley lens therefore larger angle of view.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-07-03

    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-10-03

    Hale-Bopp 10.3.
    f=55mm/1:1.8, Fujichrome 400, exposure 30s with fixed camera, Georgsmarienhütte/Holzhausen, A. Hänel

    1997-11-03

    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking.

    1997-21-03

    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=5 Pixel).

    1997-29-03

    Hale-Bopp 29.3. Foto 100mm
    f=100mm/1:4, 19:30 UT, exp. 5m., Fujichrome 400, Georgsmarienhütte/Holzhausen, A. Hänel

    1997-31-03

    Hale-Bopp 31.3. Foto 200mm
    f=200mm/1:4, 19:40 UT, exp. 5m, Scotchchrome 400, Oldendorfer Berg, A. Hänel, W. Haller
    Hale-Bopp original
    original, exp. 6s, red filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-01-04

    Hale-Bopp 1.4. Foto 200mm
    f=200mm/1:4, exp. 5m, Kodak Gold 400, Oldendorfer Berg, A. Hänel

    1997-02-04

    Hale-Bopp and Mercury 2.4.. Foto 55mm
    Hale-Bopp high in the sky and Mercury low near the horizon
    f=55mm/1:4, exp. 20s, Kodak Gold 400, Oldendorfer Berg, A. Hänel
    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-03-04

    Hale-Bopp original
    original, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-06-04

    Hale-Bopp 6.4. Foto 200mm
    f=200mm/1:4, 21:12 UT, exp. 10m., Kodak Gold 400, Oldendorfer Berg, A. Hänel

    Hale-Bopp 6.4. Foto 55mm
    with h + chi Perseus, f=55mm/1:4, 21: UT, exp. 6m., Kodak Gold 400, Oldendorfer Berg, A. Hänel
    Hale-Bopp original
    originalbild, exp. 1s, without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-07-04

    Hale-Bopp 7.4. Foto 200mm
    f=200mm/1:4, 21:02 UT, exp. 6m, Fujichrome 400, Georgsmarienhütte/Holzhausen, A. Hänel

    1997-09-04

    Hale-Bopp 9.4. Foto 200mm
    f=200mm/1:4, 21:15 UT, exp 5m, Fujichrome 400, Oldendorfer Berg, A. Hänel
    Hale-Bopp original
    original, 2 x 3s exp., without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-15-04

    Hale-Bopp original
    original, exp. 5s, red filter

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-16-04

    Hale-Bopp original
    original, 2 x 6s exp., without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    1997-01-05

    Hale-Bopp 1.5. Foto 200mm
    f=200mm/1:4, 20:30 UT, exp. 3m, Fujichrome 400, Georgsmarienhütte/Holzhausen, A. Hänel

    1997-02-05

    Hale-Bopp original
    original, 2 x 10s exp., without filter.

    Hale-Bopp rotation radial-shift algorithm
    rotation radial-shift algorithm.
    Hale-bopp unsharp masking
    unsharp masking (SIGMA=10 Pixel).

    Radial and rotational shift algorithm (Larson & Sekanina)

    This method has been used first by Larson and Sekanina in ApJ. 89, 571, 1984 to reveal small intensity fluctuations in the coma of comet Halley exposures from 1910. Later they used it also on CCD exposures of Halley in 1986.
    This algorithm is implemented in the program MiPS of Chritian Buil and others, that we use. First the intensity maximum (brightest pixel) in the image is searched. The original picture is rotated by a certain angle (we used 10°) clockwise and counterclockwise around the intensity maximum. They are shifted by a certain amount (we used 1 pixel). These two pictures are subtracted from the original, that has been multiplied with a factor of two. By this method the strong radial intensity gradient in the coma is suppressed and smaller fluctuations like jets etc. can be recognized!

    Unsharp masking

    The original image is convolved with a two-dimensional Gaussian function of width SIGMA (in pixels), resulting in a smeared image (also implemented in MiPS). Subtracting this image from the original also reduces the strong radial intensity gradient in the coma and reveals smaller intensity fluctuations.

    Authors of the images

    Erwin Heiser, Rosengasse 9, D-49082 Osnabrück, eheiser@os-net.de
    Dr. Andreas Hänel, Museum am Schölerberg, Am Schölerberg 8, D-49082 Osnabrück, ahaenel@rz.uni-osnabrueck.de

    Links

    Some links with further informations

    Page by Dr. Andreas Hänel - ahaenel@rz.uni-osnabrueck.de.

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