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Published October 10, 2025 | Version Published
Journal Article Open

Possible First Detection of Gyroresonance Emission from a Coronal Mass Ejection in the Middle Corona

Creators

  • 1. ROR icon New Jersey Institute of Technology
  • 2. ROR icon University Corporation for Atmospheric Research
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon Jet Propulsion Lab
  • 5. ROR icon Arizona State University
  • 6. ROR icon George Mason University
  • 7. ROR icon University of New Mexico
  • 8. Real-Time Radio Systems Ltd, Bournemouth, Dorset BH6 3LU, UK
  • 9. ROR icon Rice University

Abstract

Routine measurements of the magnetic field of coronal mass ejections (CMEs) have been a key challenge in solar physics. Making such measurements is important both from a space weather perspective and for understanding the detailed evolution of the CME. In spite of significant efforts and multiple proposed methods, achieving this goal has not been possible to date. Here we report the first possible detection of gyroresonance emission from a CME. Assuming that the emission is happening at the third harmonic, we estimate that the magnetic field strength ranges from 7.9 to 5.6 G between 4.9 and 7.5 R⊙. We also demonstrate that this high magnetic field is not the average magnetic field inside the CME, but most probably is related to small magnetic islands, which are also being observed more frequently with the availability of high-resolution and high-quality white-light images.

Copyright and License

© 2025. The Author(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.

Acknowledgement

S.M., B.C., and D.G. were supported by the NASA Living With a Star (LWS) Science grant 80NSSC24K1116. The OVRO-LWA expansion project was supported by NSF under grant AST-1828784. OVRO-LWA operations for solar and space weather sciences are supported by NSF under grant AGS-2436999. P.Z. acknowledges support for this research by the NASA Living with a Star Jack Eddy Postdoctoral Fellowship Program, administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award 80NSSC22M0097. A portion of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). A portion of this work was supported by the National Science Foundation Graduate Research Fellowship under Grant No. 2139433. The authors also thank the referee for suggestions which have improved the quality of the manuscript.

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Additional details

Related works

Is new version of
Discussion Paper: arXiv:2509.16453 (arXiv)

Funding

National Aeronautics and Space Administration
80NSSC24K1116
National Science Foundation
AST-1828784
National Science Foundation
AGS-2436999
University Corporation for Atmospheric Research
National Aeronautics and Space Administration
80NSSC22M0097
National Aeronautics and Space Administration
80NM0018D0004
National Science Foundation
2139433

Dates

Accepted
2025-09-09

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Caltech groups
Astronomy Department, Owens Valley Radio Observatory, Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published