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Information × Registration Number 0214U005843, 0114U002998 , R & D reports Title Investigation of cometary of Solar system bodies at large heliocentric distances popup.stage_title Head Korsun Pavlo P., Registration Date 22-12-2014 Organization Main Astronomical Observatory popup.description2 An original model of comet dust tail formation, which was developed by the authors of the project, was used to determine the physical parameters of dust environment of comet C/2006 S3 (LONEOS) and Centaur 174P/Echeclus. The model bases on statistical approach and describes probabilistic active physical processes on nucleus surfaces. The model was successfully applied for the analysis of the dust environments of some comets. The analysis of the images of C/2006 S3 (LONEOS) led to the conclusion that the cometary activity could be explained by outflow of the dust particles from two active areas. One of them had been active since the moment of discovery and supplied the most of the dust into the cometary coma and tail. The dust outflow from this zone was non-collimated. An additional zone was activated in the beginning of 2013. Dust particles were emitted inside a cone having a half-width of 30°. The physical properties of the dust particles emitted from both zones were similar and were in agreement with Greenberg's model of cometary dust particles. It was proved that the sizes of the particles fell in a range of 5-1000 m, the size particle distribution obeyed a power law with a power index of -3.5, and the outflow velocities of the particles equaled to approximately tens of meters per second. The morphology of the Centaur image can be explained by two short-lasting processes on the nucleus surface, which acted inside a short time span around December 7, 2005. Since the processes lasted no longer than several hours, the outflows from these zones stopped by December 2005 and by March 2007. Therefore, only the dust cloud was seen in the images as a remnant of these processes. The short time span of the active processes leads to the conclusion that it could be collision events like in the case of comet 9P/Tempel 1 during Deep Impact Mission. Non-collimated source of the ejected particles became active earlier, around November 15, 2005. Growth of the activity of this source till its maximum was steep followed by gradual decrease of dust production. Although this active zone faded by March, 2006, it was still active at much lower level comparing to its maximum, which was recorded in December, 2005. Some parameters of the active sources and properties of the dust particles such as the range of particle sizes, the size distribution function, and the particle ejection velocities are different for these active zones. Product Description popup.authors Іванова О. В. Корсун П. П. Кулик І. В. popup.nrat_date 2020-04-02 Close