1. Structure and evolution of the diamagnetic cavity at comet 67P/Churyumov–Gerasimenko
- Author
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Hans Nilsson, Christoph Koenders, Charlotte Goetz, Bruce T. Tsurutani, Chris Carr, Holger Sierks, Pierre Henri, Dennis Frühauff, Kirk C. Hansen, Ingo Richter, Anders Eriksson, Martin Volwerk, Martin Rubin, Karl-Heinz Glassmeier, Carsten Güttler, James L. Burch, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Southwest Research Institute [San Antonio] (SwRI), Space and Atmospheric Physics Group [London], Blackett Laboratory, Imperial College London-Imperial College London, Swedish Institute of Space Physics [Uppsala] (IRF), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, and Science and Technology Facilities Council (STFC)
- Subjects
010504 meteorology & atmospheric sciences ,530 Physics ,ROSETTA PLASMA CONSORTIUM ,Comet ,Astrophysics ,Astronomy & Astrophysics ,ROSINA ,magnetic fields ,01 natural sciences ,REGION ,Fusion, plasma och rymdfysik ,comets: individual: 67P ,individual: 67P [comets] ,0103 physical sciences ,data analysis [methods] ,ION ,PROBE ,010303 astronomy & astrophysics ,Short duration ,HALLEY ,MAGNETOMETER ,0105 earth and related environmental sciences ,Physics ,Science & Technology ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,520 Astronomy ,Astronomy ,Astronomy and Astrophysics ,Plasma ,620 Engineering ,plasmas ,Fusion, Plasma and Space Physics ,methods: data analysis ,[PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph] ,Magnetic field ,0201 Astronomical And Space Sciences ,13. Climate action ,Space and Planetary Science ,SOLAR-WIND ,Physical Sciences ,MAGNETIC CAVITY ,Diamagnetism ,Astrophysics::Earth and Planetary Astrophysics ,PERIHELION - Abstract
International audience; The long duration of the Rosetta mission allows us to study the evolution of the diamagnetic cavity at comet 67P/Churyumov–Gerasimenko in detail. From 2015 April to 2016 February 665 intervals could be identified where Rosetta was located in a zero-magnetic-field region. We study the temporal and spatial distribution of this cavity and its boundary and conclude that the cavity properties depend on the long-term trend of the outgassing rate, but do not respond to transient events at the spacecraft location, such as outbursts or high neutral densities. Using an empirical model of the outgassing rate, we find a functional relationship between the outgassing rate and the distance of the cavity to the nucleus. There is also no indication that this unexpectedly large distance is related to unusual solar wind conditions. Because the deduced shape of the cavity boundary is roughly elliptical on small scales and the distances of the boundary from the nucleus are much larger than expected we conclude that the events observed by Rosetta are due to a moving instability of the cavity boundary itself.
- Published
- 2017
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