DPS 2001 meeting, November 2001
Session 20. Comet Posters
Displayed, 9:00am Tuesday - 3:00pm Saturday, Highlighted, Wednesday, November 28, 2001, 10:30am-12:30pm, French Market Exhibit Hall

## [20.05] Rotation of Comet 81P/Wild 2

J. Pittichová, K. J. Meech (IfA)

81P/Wild 2 is the STARDUST space mission target. This comet was selected because of its newness as a Jupiter family comet and because of the discovery of a trajectory offering a low encounter velocity of only 6.1 km s-1. Observations over a wide range of heliocentric distances since 1987 have enabled us to greatly enhance our knowledge of 81P/Wild 2, as required to mount a successful space mission. We will present four sets of observations of comet 81P/Wild 2 which were made in order to search for the nucleus rotational period during November 11--12, 1996, June 26--28, 1998, September 26--28, 1998 and August 12--17, 1999 using the University of Hawaii 2.2m telescope. At the time of the observations, the comet was at heliocentric distances, r = 2.28, 3.61, 4.01 and 4.98 AU. The comet was active for all runs, and during 1996 November the coma extended > 100'' (1.65 \times 105 km at the distance of the comet) at PA \approx 262\circ, and during 1996 June the coma extended > 51'' (1.34 \times 105 km at the distance of the comet) at PA \approx 254\circ, and during 1998 September the coma extended > 12'' (3.50 \times 104 km at the distance of the comet) at PA \approx 125\circ, and during 1999 August the coma extended > 8'' (2.90 \times 104 km at the distance of the comet) at PA \approx 203\circ. Using a phase-dispersion minimization technique, we will report on possible rotation periods.

This work was supported by NASA Grants NAGW-5015, NAG5-4495, and by the NASA Stardust mission (JPL Contract 1216682).