Planetary Group Seminar: Studies of photometry and cometary activity of Churyumov-Gerasimenko comet by means of Rosetta/VIRTIS and Rosetta/GIADA pre-perihelion data (A. Longobardo)
11:00 - 12:00
The cometary activity of 67P/Churyumov-Gerasimenko (67P/CG) during the Rosetta pre-landing phase is investigated using data from GIADA’s dust instrument subsystems (the Grain Detector System (GDS) and the Impact Sensor (IS) subsystems) and from the VIRTIS instrument on Rosetta. VIRTIS data are used to infer the photometric behavior of spectral parameters describing the spectrum of 67P/CG, and variations of this behavior among the four comet macro-regions (i.e. head, neck, body, bottom) and with local time. Our results based on GIDA data show a good correlation between the fluffy and compact particles, indicating that the source of the two different types of dust particles is likely the same. This correlation is not maintained in the coma, where fluffy and compact distributions are different. A correlation is also found between number of particles detected by GIADA and the spectral shift of the 3.2 mm band observed by VIRTIS in each comet region observed during the considered period, corroborating that the band center shift with temperature is likely due to the diurnal pre-perihelion cometary activity. We explain the used methods and discuss the found results.