The following document lists the file abstract/DOSIP_COM_SPEC.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
===================================================================== ==> In this proposal, more time is being requested for DOSIP.PROP_COM ===================================================================== The study of comets is of great importance to our understanding of the solar system and its origin. Comets comprise the most primitive material in the solar system and observations of their composition are diagnostic of the environment in which they formed. In recent taxonomic classification of comets, we have clearly separated out the majority ( 70%) of comets having "typical" molecular abundances from a second distinct class of comets that exhibit significant depletions in the carbon-chain species (C2 and C3). The ISO Guaranteed Time target, P/Kopff, as well as the Target of Opportunity (ToO) comet Hale-Bopp are members of the "typical" class of comets. Members of the "carbon-chain depleted" class of comets must be studied in similar detail as those of the "typical" class if we are indeed to gain a firm understanding of the processes that took place during the early solar system. Two of the three most extreme members of the the "carbon-chain depleted" class are positioned favorably for observations by ISO. We are currently scheduled for November 1996 observations of comet P/IRAS in order to complement the existing Guaranteed time observations (DOSIP.PROP_COM). Here, we propose to extend the previously awarded time to also observe P/Wolf-Harrington which is the most extreme member of the carbon-chain depleted class of comets and was our primary Spring Launch target. This target has gas and dust production levels approximately a factor of 3-5 below that of the principal GTO target, P/Kopff and about 1% the production of P/Halley. Results from this observational programme are highly complementary to the Guaranteed Time Observations of comets (EGRUEN.COMETS) as well as our current open time observations (DOSIP.PROP_COM).