Energetic ions in the Venusian system: Insights from the first Solar Orbiter flyby

0551014 - ÚFA 2022 RIV FR eng J - Journal Article
Allen, R.C. - Cernuda, I. - Pacheco, D. - Berger, L. - Xu, Z. G. - Freiherr Von Forstner, J. L. - Rodríguez-Pacheco, J. - Wimmer-Schweingruber, R. F. - Ho, G.C. - Mason, G.M. - Vines, S. K. - Khotyaintsev, Y. - Horbury, T. - Maksimovic, M. - Hadid, L. Z. - Volwerk, M. - Dimmock, A.P. - Sorriso-Valvo, L. - Stergiopoulou, K. - Andrews, G. B. - Angelini, V. - Bale, S. D. - Boden, S. - Böttcher, S. I. - Chust, T. - Eldrum, S. - Espada, P. P. - Espinosa Lara, F. - Evans, V. - Gómez-Herrero, R. - Hayes, J. R. - Hellín, A. M. - Kollhoff, A. - Krasnoselskikh, V. - Kretzschmar, M. - Kühl, P. - Kulkarni, S. R. - Lees, W. J. - Lorfèvre, E. - Martin, C. - O'Brien, H. - Plettemeier, D. - Polo, O. R. - Prieto, M. - Ravanbakhsh, A. - Sánchez-Prieto, S. - Schlemm, C. E. - Seifert, H. - Souček, Jan - Steller, M. - Štverák, Štěpán - Terasa, J. C. - Trávníček, P. - Tyagi, K. - Vaivads, A. - Vecchio, A. - Yedla, M.
Energetic ions in the Venusian system: Insights from the first Solar Orbiter flyby.
Astronomy & Astrophysics. Roč. 656, Dec 14 (2021), č. článku A7. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:68378289 ; RVO:67985815
Keywords : acceleration of particles * terrestrial planets * planet-star interaction * planetary systems * turbulence * waves
OECD category: Fluids and plasma physics (including surface physics); Astronomy (including astrophysics,space science) (ASU-R)
Impact factor: 6.240, year: 2021
Method of publishing: Open access
https://www.aanda.org/component/article?access=doi&doi=10.1051/0004-6361/202140803

The Solar Orbiter flyby of Venus on 27 December 2020 allowed for an opportunity to measure the suprathermal to energetic ions in the Venusian system over a large range of radial distances to better understand the acceleration processes within the system and provide a characterization of galactic cosmic rays near the planet. Bursty suprathermal ion enhancements (up to ∼10 keV) were observed as far as ∼50RV downtail. These enhancements are likely related to a combination of acceleration mechanisms in regions of strong turbulence, current sheet crossings, and boundary layer crossings, with a possible instance of ion heating due to ion cyclotron waves within the Venusian tail. Upstream of the planet, suprathermal ions are observed that might be related to pick-up acceleration of photoionized exospheric populations as far as 5RV upstream in the solar wind as has been observed before by missions such as Pioneer Venus Orbiter and Venus Express. Near the closest approach of Solar Orbiter, the Galactic cosmic ray (GCR) count rate was observed to decrease by approximately 5 percent, which is consistent with the amount of sky obscured by the planet, suggesting a negligible abundance of GCR albedo particles at over 2 RV. Along with modulation of the GCR population very close to Venus, the Solar Orbiter observations show that the Venusian system, even far from the planet, can be an effective accelerator of ions up to ∼30 keV. This paper is part of a series of the first papers from the Solar Orbiter Venus flyby.
Permanent Link: http://hdl.handle.net/11104/0326296