The birth and growth of a solar wind cavity around a comet – Rosetta observations. (27th July 2017)

• Record Type: Journal Article
• Authors: Behar, E.; Nilsson, H.; Alho, M.; Goetz, C.; Tsurutani, B.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 469(2017)Supplement 2
• Page Start: S396
• Page End: S403
• Publication Date: 2017-07-27
• Subjects: acceleration of particles -- plasmas -- methods: data analysis -- techniques: imaging spectroscopy -- comets: individual: 67P/Churyumov–Gerasimenko; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx1871
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: The Rosetta mission provided detailed observations of the growth of a cavity in the solar wind around comet 67P/Churyumov–Gerasimenko. As the comet approached the Sun, the plasma of cometary origin grew enough in density and size to present an obstacle to the solar wind. Our results demonstrate how the initial slight perturbations of the solar wind prefigure the formation of a solar wind cavity, with a particular interest placed on the discontinuity (solar wind cavity boundary) passing over the spacecraft. The slowing down and heating of the solar wind can be followed and understood in terms of single particle motion. We propose a simple geometric illustration that accounts for the observations, and shows how a cometary magnetosphere is seeded from the gradual steepening of an initially slight solar wind perturbation. A perspective is given concerning the difference between the diamagnetic cavity and the solar wind cavity.