Comet Hale Bopp gas distribution

In the course of the continuing observational programme at the ESO La Silla Observatory in the Chilean Atacama desert, CCD frames of Comet Hale-Bopp were obtained on 1 October 1997 with the 2.2-m ESO/MPI telescope. These images show only the central part of the well developed cloud of gas and dust (the coma) around the cometary nucleus (the 'dirty snowball' of ice and dust). The field of view is about 3 x 3 arcmin, corresponding to about 1/100th of the full moon area in the sky. At the present distance of the comet from the Earth, about 3.1 AU or 465 million km, this field corresponds to about 400,000 x 400,000 km. The coma of the comet is still much larger and extends far beyond the border of this image.