Orbital elements of the material surrounding comet 67P/Churyumov-Gerasimenko

Björn Davidsson 1 Pedro J. Gutierrez 2 Holger Sierks 3 Cesare Barbieri 4, 5 Philippe Lamy 6 Rafael Rodrigo 7, 8 Detlef Koschny 9 Hans Rickman 10, 1 Horst U. Keller 11 Jessica Agarwal 3 Michael F. A’hearn 12, 13, 3 Maria Antonietta Barucci 14 Jean-Loup Bertaux 15 Ivano Bertini 5 Dennis Bodewits 13 Gabriele Cremonese 16 Vania Da Deppo 17 Stefano Debei 18 Mariolino De Cecco 19 Sonia Fornasier 14, 20 Marco Fulle 21 Olivier Groussin 6 Carsten Güttler 3 Stubbe F. Hviid 22 Wing-Huen Ip 23 Laurent Jorda 6 Jörg Knollenberg 22 G. Kovacs 3 J. Rainer Kramm 3 Ekkehard Kürt 22 Michael Küppers 24 Fiorangela La Forgia 4 Luisa M. Lara 2 Monica Lazzarin 4 Jose J. Lopez-Moreno 2 S. Lowry 25 Sara Magrin 4 Francesco Marzari 4 Harald Michalik 26 R. Moissl–fraund 24 Giampiero Naletto 18 Nilda Oklay 3 Maurizio Pajola 5 Colin Snodgrass 27 Nicholas Thomas 28 Cecilia Tubiana 3 Jean-Baptiste Vincent 3
Abstract : We investigate the dust coma within the Hill sphere of comet 67P/Churyumov-Gerasimenko. Aims. We aim to determine osculating orbital elements for individual distinguishable but unresolved slow-moving grains in the vicinity of the nucleus. In addition, we perform photometry and constrain grain sizes. Methods. We performed astrometry and photometry using images acquired by the OSIRIS Wide Angle Camera on the European Space Agency spacecraft Rosetta. Based on these measurements, we employed standard orbit determination and orbit improvement techniques. Results. Orbital elements and effective diameters of four grains were constrained, but we were unable to uniquely determine them. Two of the grains have light curves that indicate grain rotation. Conclusions. The four grains have diameters nominally in the range 0.14–0.50 m. For three of the grains, we found elliptic orbits, which is consistent with a cloud of bound particles around the nucleus. However, hyperbolic escape trajectories cannot be excluded for any of the grains, and for one grain this is the only known option. One grain may have originated from the surface shortly before observation. These results have possible implications for the understanding of the dispersal of the cloud of bound debris around comet nuclei, as well as for understanding the ejection of large grains far from the Sun.
Type de document :
Article dans une revue
Astronomy and Astrophysics - A&A, EDP Sciences, 2015, 583, A16 (9 p.). 〈10.1051/0004-6361/201525841〉
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Soumis le : lundi 21 septembre 2015 - 10:41:25
Dernière modification le : jeudi 14 juin 2018 - 10:54:03

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Björn Davidsson, Pedro J. Gutierrez, Holger Sierks, Cesare Barbieri, Philippe Lamy, et al.. Orbital elements of the material surrounding comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics - A&A, EDP Sciences, 2015, 583, A16 (9 p.). 〈10.1051/0004-6361/201525841〉. 〈insu-01202463〉



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