Comet Halley at 1,250 million kilometres

This picture of famous Comet Halley was obtained with the Danish 1.5 m telescope at the ESO La Silla observatory during April-May 1988. It has been produced by the combination of about 50 CCD frames, obtained during 19 nights, totalling 11 hours 35 minutes exposure. It shows the comet in visual light at a distance of about 1,250 million kilometres. Left: Smoothed picture with 6 light levels, in order to show the 23-mag cometary nucleus in the asymmetric, inner coma and also the much larger, elongated outer coma. Right: Three-dimensional representation, illustrating the relative brightness of the nucleus, as compared to the coma. The field of the picture measures 75 arcsec 75 arcsec; North is up and East is to the left. The direction to the Sun is WNW.

Technical information: Pixel size: 0.47 arcsec = 2,800 km. Johnson V filter. Bias-subtracted, flat-fielded, cleaned for cosmic events, stars and galaxies removed, 3 pix 3 pix gaussian smoothed. (ESO Press Release eso8804; BW and Colour)