ESO Images of Comet Hale-Bopp (May 14, 1996)
20 mei 1996
Observations of Comet 1995 O1 (Hale-Bopp) continued at ESO during the period of May 10 - 14, 1996, with the MPI/ESO 2.2-m telescope and the multimode EFOSC II instrument. Both direct images and spectra were obtained.
A provisional evaluation of these observations shows that the comet 'is still going (very) strong' and that the dust and gas production continues at comparatively high rates. Together with recent magnitude estimates, it is evident that the comet is following a normal development and there are still no signs at present of a decrease of the activity level.
If the current development continues, a straight extrapolation indicates that Comet Hale-Bopp may reach negative magnitudes near perihelion in April 1997, possibly around -2. However, this prediction is of course still very uncertain and it will be necessary to follow the comet closely with all available observational means during 1996.
A series of images through the standard filters B (Blue), V (Green-Yellow) and R (Red) was obtained with the 2.2-m telescope on May 14.25 UT. One of the R-images is reproduced here in false-colours as eso9627a. The central part has been further processed as eso9627b to show the asymmetrical component; here an enormous dust jet, emanating northwards of the nucleus, is clearly visible. The fields shown are 200 x 190 arcsec and 68 arcsec (diameter), respectively. On both images, north is up and east is to the left; 1 pixel = 0.336 arcsec.
At the time of the exposure, the comet was about 573 million km from the Earth and 661 million km from the Sun. On the sky, it was steadily moving north through the constellation of Sagittarius (The Archer) and will soon be crossing the border into Aquila (The Eagle).