Long-lived Magnetic Switchbacks Tracked across 0.32 au through BepiColombo–Solar Orbiter Radial Alignment
Year: 2025
Type: article
Abstract: Magnetic switchbacks, often observed in the near-Sun solar wind, have received increased interest in recent years due to their potential role in mediating the heating and acceleration of the solar wind, but their origin remains debated. In this work, we present a coordinated observation of a switchback cluster by BepiColombo (0.35 au) and Solar Orbiter (0.67 au), obtained during the alignment between 2021 October 6 and 8, which enabled the first direct investigation of switchback evolution across heliocentric distances. In particular, the stream observed by the spacecraft can be tracked back to the boundary of an equatorial coronal hole. Large-scale switchbacks exhibit strong sublinear expansion, thus appearing almost unevolved in morphology during the propagation when the spacecraft cutting-angle effect is taken into account. The stable magnetic configuration of the analyzed switchbacks suggests that they can be identified as small-scale flux ropes. Indeed, for shear-driven instabilities triggered by stream interaction with the background slow wind, short-living (one eddy turnover time, τ ∼ 1 hr) switchbacks would be expected compared to the travel time from BepiColombo to Solar Orbiter (∼38 hr). These findings provide critical insights on switchback origin and evolution, potentially constraining future phenomenologies on their formation. A useful consequence of our observations is that statistical analyses on switchback evolution should always account for the cutting-angle effect.
Authors: Mirko Stumpo, Simone Benella, Pier Paolo Di Bartolomeo, Andrea Larosa, Oreste Pezzi, Georgios Nicolaou, Domenico Trotta, Tommaso Alberti, Raffaella D’Amicis, Monica Laurenza, Andrea Verdini, Anna Milillo, Daniel Heyner, Alessandro Aronica, Lorenzo Biasiotti, Alessandro Brin, Luca Colasanti, Elisabetta De Angelis, Stavro Ivanovski, Adrian Kazakov, Valeria Mangano, Stefano Massetti, Martina Moroni, Alessandro Mura, Christina Plainaki, Grace Richards, Rosanna Rispoli, Roberto Sordini, H. U. Auster, D. Constantinescu, D. Fischer, I. Richter
Institutions: Institute for Space Astrophysics and Planetology, National Institute for Astrophysics, Institute for the Science and Technology of Plasmas, National Research Council, University College London, European Space Agency, European Space Astronomy Centre, Istituto Nazionale di Geofisica e Vulcanologia, University of Florence, Technische Universität Braunschweig, Trieste Astronomical Observatory, Agenzia Spaziale Italiana, Max Planck Institute for Solar System Research, Space Research Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,400
Funders: National Aeronautics and Space Administration, UK Space Agency, European Space Agency, European Commission, Centre National d’Etudes Spatiales, Agenzia Spaziale Italiana, Centre National de la Recherche Scientifique, Istituto Nazionale di Astrofisica, Observatoire de Paris, Université de Recherche Paris Sciences et Lettres, Science and Technology Facilities Council
Awards: G8816549862, G972786147
OpenAlex ID: W7116720987