Comet Hyakutake develops two tails

The present photo is the first to show the turn-on of the ion tail (this is the technical term for this event). It is a reproduction of a 15-min CCD exposure obtained by ESO-astronomer Ferdinando Patat on Feb. 16.35 UT with the Danish 1.54-m telescope and the DFOSC multimode instrument (2k x 2k pix CCD) at the ESO La Silla Observatory. An R-filtre was used. The frame was image-processed at the ESO office in Santiago de Chile by another ESO-astronomer, Stefano Benetti, and then transferred to ESO Garching. The field measures 10.4 x 10.4 arcmin; the scale is 0.39 arcsec/pix; North is up and East is to the left.