Search Publications
Cometary dust properties retrieved from polarization observations: Application to C/1995 O1 Hale Bopp and 1P/Halley
Lasue, J.; Levasseur-Regourd, A. C.; Hadamcik, E. +1 more
The analysis of the polarized light scattered by cometary dust particles provides information on the physical properties of the solid component of cometary comae for C/1995 O1 Hale-Bopp and 1P/Halley. A model of light scattering by a size distribution of aggregates of up to 256 submicron-sized grains (spherical or spheroidal) mixed with single sph…
Ion composition and chemistry in the coma of Comet 1P/Halley—A comparison between Giotto's Ion Mass Spectrometer and our ion-chemical network
Hansen, Kenneth C.; Gombosi, Tamas I.; Combi, Michael R. +3 more
In order to understand the cometary plasma environment it is important to track the closely linked chemical reactions that dominate ion evolution. We used a coupled MHD ion-chemistry model to analyze previously unpublished Giotto High Intensity Ion Mass Spectrometer (HIS-IMS) data. In this way we study the major species, but we also try to match s…
Optical properties of dust from Jupiter family comets
Levasseur-Regourd, A. C.; Hadamcik, E.
To try to define specific physical properties of the dust of Jupiter-family comets (JFCs), we compare the light scattered by them. Amongst the more than 1000 JFCs, less than 200 are numbered, 40 of them being rather bright. In the present work we use data from the latter. In situ observations of three nuclei show low albedo surfaces. The albedo of…
Probing the internal structure of the nuclei of comets
Lasue, J.; Levasseur-Regourd, A. C.; Hadamcik, E. +1 more
There is no direct evidence about the internal structure of cometary nuclei, which are mostly hidden by their gas and dust comae, and have not yet been orbited by any spacecraft. Their densities are low, typically of about 400 kg m -3 for 9P/Tempel 1 (that was impacted by the Deep Impact probe) and 67P/Churyumov-Gerasimenko (that is the…