67P/Churyumov-Gerasimenko Spectrophotometric Properties

Thursday, 18 December 2014
Sebastien Besse1, Sonia Fornasier2, Holger Sierks3, M. Antonietta Barucci2, Cedric Leyrat4, Stubbe Faurschou Hviid5, Laurent Jorda6, Horst Uwe Keller7, Michael Küppers1, Sara Magrin8, Matteo Massironi9, Nilda Oklay3, M. Pajola10, Nicolas Thomas11, C. Tubiana3, Colin Snodgrass12 and Jean-Baptiste Vincent13, (1)European Space Agency, Villanueva De La Can, Spain, (2)LESIA Observatoire de Paris, Meudon, France, (3)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (4)Paris Observatory Meudon, Meudon, France, (5)German Aerospace Center DLR Berlin, Berlin, Germany, (6)Observatoire Astrophysique Marseille, Marseille, France, (7)Technical University of Braunschweig, Braunschweig, Germany, (8)CISAS - Center for Studies and Activities for Space, University of Padova, Padova, Italy, (9)Univ Padova, Padova, Italy, (10)CISAS-University of Padova, Padova, Italy, (11)University of Bern, Bern, Switzerland, (12)Max-Planck Institute for Solar System Research, Goettingen, Germany, (13)Max-Planck Institute for Solar System Research, Germany, Goettigen, Germany
On August 6th 2014, the Rosetta spacecraft entered orbit around the nucleus of comet 67P/Churyumov-Gerasimenko. During its approach, the Optical Spectroscopic and Infrared Remote Imaging System (OSIRIS) observed the nucleus with various illumination conditions and filters to characterize the surface. Observations with resolution of the order of 1m/pixel are scheduled before the end of the year 2014; they will provide incredible detail of the cometary nucleus’s surface. The mineralogical and photometric properties of the surface are very important scientific topics to understand the properties of the nucleus, the formation and evolution of its surface, and its relationship with the activity of the comet

Here we will present the results of the spectrophotometry obtained with 11 filters covering the 250-1000 nm range (obtained through the Narrow Angle Camera NAC), and of the photometric analysis of the surface of the cometary nucleus taken between July and November 2014. Images span various phase angles (including opposition) and various resolutions, and cover the entire surface of the nucleus. These observations will allow the first global and detailed spectrophotometric characterization of a comet nucleus. Of particular interest is the identification of ices on the surface or not, the mineralogical differences between the two lobes of the nucleus if any, and the global photometric properties.