On the rotation of the IRAS-Araki-Alcock nucleus

The nuclear rotation of the comet C/1983 H1 IRAS-Araki-Alcock (1983 VII) has been investigated from 166 RCA CCD exposures taken with the 61 -cm telescope at the Whipple Observatory from May 6 through May 11, 1983. Application of image processing methods shows the presence of a fan-like coma with three jets. The features in the coma rotated in a clockwise direction. The fan with the three jets originated near the south pole of the nucleus. During the observation period, the orientations of the jets and the fanshaded coma suggested that nuclear precession was probably also present. On May 9–10 the nucleus had an outburst.