Observations and analysis of a curved jet in the coma of comet 67P/Churyumov-Gerasimenko

¹ Institute of Astronomy, National Central University, 32054 Chung-Li, Taiwan
e-mail: zylin@astro.ncu.edu.tw
² Institute of Space Sciences, National Central University, 32054 Chung-Li, Taiwan
³ Department of Mechanical Engineering, National Chiao Tung University, Taiwan
⁴ Space Science Institute, Macau University of Science and Technology, Macau
⁵ Dept. of Earth Science, National Central University, 32054 Chung-Li, Taiwan
⁶ Max-Planck Institut für Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077 Göttingen, Germany
⁷ Department of Physics and Astronomy “G. Galilei”, University of Padova, Vic. Osservatorio 3, 35122 Padova, Italy
⁸ Centro di Ateneo di Studi ed Attivitá Spaziali “Giuseppe Colombo”, University of Padova, via Venezia 15, 35131 Padova, Italy
⁹ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astro-physique de Marseille) UMR 7326, 13388 Marseille, France
¹⁰ Centro de Astrobiologia (INTA-CSIC), European Space Agency (ESA), European Space Astronomy Centre (ESAC), PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
¹¹ International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland
¹² Research and Scientific Support Department, European Space Agency, 2201 Noordwijk, The Netherlands
¹³ PAS Space Research Center, Bartycka 18A, 00716 Warszawa, Poland
¹⁴ Institut für Geophysik und extraterrestrische Physik (IGEP), Technische Universität Braunschweig, 38106 Braunschweig, Germany
¹⁵ Department for Astronomy, University of Maryland, College Park, MD 20742-2421, USA
¹⁶ LESIA-Observatoire de Paris, CNRS, UPMC Univ. Paris 06, Univ. Paris-Diderot, 5 place J. Janssen, 92195 Meudon Principal Cedex, France
¹⁷ LATMOS, CNRS/UVSQ/IPSL, 11 Boulevard dAlembert, 78280 Guyancourt, France
¹⁸ INAF Osservatorio Astronomico di Padova, vic. dell’Osservatorio 5, 35122 Padova, Italy
¹⁹ CNR-IFN UOS Padova LUXOR, via Trasea 7, 35131 Padova, Italy
²⁰ Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
²¹ Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
²² University of Trento, via Sommarive 9, 38123 Trento, Italy
²³ INAF–Osservatorio Astronomico di Trieste, via Tiepolo 11, 34143 Trieste, Italy
²⁴ Instituto de Astrofísica de Andalucía (CSIC), c/Glorieta de la Astronomía, 18008 Granada, Spain
²⁵ Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Planetenforschung, Rutherfordstrasse 2, 12489 Berlin, Germany
²⁶ Centre for Astrophysics and Planetary Science, School of Physical Sciences, The University of Kent, Canterbury CT2 7NH, UK
²⁷ Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy
²⁸ Physikalisches Institut der Universität Bern, Sidlerstr. 5, 3012 Bern, Switzerland

Received: 19 November 2015
Accepted: 28 January 2016

Abstract

Aims. We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015.

Methods. We simulated the motion of dust grains ejected from the nucleus surface under the influence of the gravity and viscous drag effect of the expanding gas flow from the rotating nucleus.

Results. The formation of the curved jet is a combination of the size of the dust particles (~0.1−1 mm) and the location of the source region near the nucleus equator. This enhances the spiral feature of the collimated dust stream after the dust is accelerated to a terminal speed on the order of m s^-1.