Comet C/1995 O1 (Hale-Bopp) at KPNO 0.9-m Telescope

NOAO/KPNO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative agreement with the National Science Foundation


image image These two pictures of Comet Hale-Bopp show structure in the distribution of dust around the comet's nucleus. The left picture is a sum of two images taken through a V filter, a filter which allows wavelengths corresponding to visible light to reach the camera. The right picture is a sum of two images taken through an R filter, a filter which allows a range of longer wavelengths to be recorded. In each of these pictures, you will notice the background stars appear as doubles. This is due to the fact that each picture is actually two images added together. The telescope was tracking the comet, not the background stars. Since the comet is moving relative to the background stars, you see displacement in the background stars while the comet is well focused and appears as a single object.

The images are 42 minutes apart and have north to the left and east to the bottom. The images were taken on September 27, 1997, at the 0.9-meter telescope from Kitt Peak National Observatory near Tucson, AZ.

image The two pictures above have been color-enhanced and overlaid to produce this color image. Many features are brought out with this type of image processing, including multiple jets which are readily seen radiating out from the comet nucleus toward the bottom of the picture. The comet's fuzzy coma displays a range of color in this enhancement, indicating a range of sizes in dust particles found in the coma. Individual background stars show as red dots. In some cases these stars are seen through the comet's coma.

The images were provided courtesy of Beatrice Mueller and Nalin Samarasinha from NOAO. Image reduction and enhancements were done by Nigel Sharp (NOAO).


image This enhanced image was produced from a broadband R image of comet Hale-Bopp taken on September 27, 1996 using the Kitt Peak 0.9-m telescope. There are at least 4 distinct dust jets (shown as white bands) present in this image radiating from the nucleus (at the center of the frame). The lack of curvature of the dust jets is suggestive of a large spin period. The coma shown in this enhanced image extends about 400,000 km from the nucleus. The ring structures present are artifacts caused by the enhancement technique and are due to stars in the field. The sun makes an angle of about 20 degrees with the line of sight and is on the same side as the earth. Both heliocentric and geocentric distances to the comet are about 2.9 AU. North is to the left and east is to the bottom. This image was taken by Beatrice Mueller and the image enhancement was done by Nalin Samarasinha.


image This image shows Comet C/1995 O1 (Hale-Bopp) observed from the Kitt Peak National Observatory 0.9-m (36-inch) telescope on 17 September 1996 using a Harris-I band filter. The image shows the comet with several different dust jets clearly visible. The sunward direction is roughly toward the top of the image. At the time this 600s image was taken, the comet was just over 3 AU from the Sun and 2.9 AU from the Earth.

The brightness of this comet, while still far away from the Sun, is an indication that this comet is large compared to most comets. The activity seen in the large number of jets, which are composed of ice, dust and gas being thrown off of the nucleus of the comet, may indicate that this comet has not been through the inner solar system very often. If this is a "fresh" comet, observations of its composition should yield important clues to the early evolution of the solar system.

The broad band images of the comet, in association with narrow band images also taken, will help determine the morphology of the comet. As part of this morphology, the astronomers will attempt to isolate any ion tail from the general dust tail seen above. The parallel spectral observations, using the KPNO 2.1-m telescope, will help to associate morphological features with spectroscopic features. This will include trying to identify ion distribution with tail features.

This image and caption were provided courtesy of Anthony Ferro, Susan Wyckoff, Rodney Heyd, and Peter Wehinger.


yellow ball A series of V, R, I frames of Comet Hale-Bopp was taken by Beatrice Mueller on August 13, 1995 using the 0.9-meter telescope on Kitt Peak. Two sets of these frames were combined to generate four color composite images of the comet. In all cases, North is up and East is left. The field of view is 2.9 arcminutes on a side at roughly RA = 18:30 and DEC = -31:30. At the time the frames were taken Hale-Bopp was 7 AU from the Sun and 6.2 AU from the Earth (for reference, Jupiter is 5.2 AU from the Sun).


Note: An AU = 1.5 X 108 km, equivalent to the mean distance of the Earth from the Sun. Mercury, the closest planet to the Sun, is at a distance of 0.39 AU from the Sun.
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Updated: 16Apr1997