46P WIRTANEN - NECESSARY OBSERVATIONS IN SUPPORT OF ROSETTA/

Knowledge of some basic properties of comet 46P/Wirtanen is vital for the successful design and execution of the International Rosetta Missi on. Specific observations to study the comet nucleus and its gas and d ust environment in detail are strongly requested during its forthcomin g apparition. 46P/Wirtanen should be regularly monitored along its orb it by means of imaging and spectroscopy at different wavelengths rangi ng from UV to radio emission. Information should be retrieved on the n ucleus (size, shape, rotation, gross surface topography), the gas and dust coma (near-nucleus morphology, composition, evolution), the comet ary activity (onset of activity, gas and dust production rates as a fu nction of heliocentric distance) and astrometric positions. An overvie w is given of the ground-based observations needed in support of ROSET TA and the observational opportunities in 1996/97. Copyright (C) 1996 Elsevier Science Ltd