Parker solar probe observations of a flux rope embedded in a near-sun heliospheric current sheet magnetic reconnection exhaust
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Published version
Author(s)
Type
Journal Article
Abstract
In situ observations by Parker Solar Probe (PSP) suggest that the heliospheric current sheet (HCS) undergoes near-continuous magnetic reconnection close to the Sun, in stark contrast to scarce observations of this phenomenon in the HCS at 1 AU. Situated at the boundary between sectors of opposite interplanetary magnetic field (IMF) polarity, reconnection in the HCS has important consequences for magnetic topology and plasma dynamics in the slow solar wind. We report observations of a reconnection outflow in the
HCS near the Alfv´en transition region in PSP’s 17th solar encounter, featuring plasma jetting, proton temperature enhancement, and electron heat flux dropout. Embedded within the exhaust is a non-force-free flux rope plasmoid exhibiting counterstreaming strahl electrons, indicating connection at both ends to the Sun in an otherwise disconnected region of magnetic field. The flux rope features diminished isotropic proton
temperature and lower bulk speed compared to the remainder of the HCS exhaust. Its oblique orientation and different plasma properties imply the flux rope originates from a different reconnection site to the HCS exhaust, suggesting PSP has intercepted
a flux-rope-like streamer blob produced at the helmet streamer. Remote observations show several comparable blobs travelling in a distant coronal ray, demonstrating the possibility that the in situ flux rope is a streamer blob. The combination of in situ and
remote observations demonstrate the role of magnetic reconnection in HCS dynamics, contributing to a growing understanding of this fundamental mechanism and its impact on the young solar wind.
HCS near the Alfv´en transition region in PSP’s 17th solar encounter, featuring plasma jetting, proton temperature enhancement, and electron heat flux dropout. Embedded within the exhaust is a non-force-free flux rope plasmoid exhibiting counterstreaming strahl electrons, indicating connection at both ends to the Sun in an otherwise disconnected region of magnetic field. The flux rope features diminished isotropic proton
temperature and lower bulk speed compared to the remainder of the HCS exhaust. Its oblique orientation and different plasma properties imply the flux rope originates from a different reconnection site to the HCS exhaust, suggesting PSP has intercepted
a flux-rope-like streamer blob produced at the helmet streamer. Remote observations show several comparable blobs travelling in a distant coronal ray, demonstrating the possibility that the in situ flux rope is a streamer blob. The combination of in situ and
remote observations demonstrate the role of magnetic reconnection in HCS dynamics, contributing to a growing understanding of this fundamental mechanism and its impact on the young solar wind.
Date Issued
2026-05-10
Date Acceptance
2026-04-09
Citation
The Astrophysical Journal (ApJ), 2026, 1002 (2), pp.1-12
ISSN
0004-637X
Publisher
IOP Publishing
Start Page
1
End Page
12
Journal / Book Title
The Astrophysical Journal (ApJ)
Volume
1002
Issue
2
Copyright Statement
© 2026. TheAuthor(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
License URL
Identifier
10.3847/1538-4357/ae5e62
Publication Status
Published
Date Publish Online
2026-04-30