Measuring the Magnetic Field of a Coronal Mass Ejection from the Low to Middle Corona

Abstract A major challenge in understanding the initiation and evolution of coronal mass ejections (CMEs) is measuring the magnetic field of the magnetic flux ropes (MFRs) that drive CMEs. Recent developments in radio imaging spectroscopy have paved the way for diagnosing the CMEs’ magnetic field using gyrosynchrotron radiation. We present magnetic field measurements of a CME associated with an X5-class flare by combining radio imaging spectroscopy data in microwaves (1–18 GHz) and meter waves (20–88 MHz), obtained by the Owens Valley Radio Observatory’s Expanded Owens Valley Solar Array (EOVSA) and Long Wavelength Array (OVRO-LWA), respectively. EOVSA observations reveal that the microwave source, observed in the low corona during the initiation phase of the eruption, outlines the bottom of the rising MFR-hosting CME bubble seen in extreme ultraviolet and expands as the bubble evolves. As the MFR erupts into the middle corona and appears as a white-light CME, its meter-wave counterpart, observed by OVRO-LWA, displays a similar morphology. For the first time, using gyrosynchrotron spectral diagnostics, we obtain magnetic field measurements of the erupting MFR in both the low and middle corona, corresponding to coronal heights of 0.02 and 1.83 R ⊙ . The magnetic field strength is found to be around 300 G at 0.02 R ⊙ during the CME initiation and about 0.6 G near the leading edge of the CME when it propagates to 1.83 R ⊙ . These results provide critical new insights into the magnetic structure of the CME and its evolution during the early stages of its eruption.

Authors

Institutions

Publication Details

Journal
The Astrophysical Journal Letters
Published
2025-09-04
DOI
https://doi.org/10.3847/2041-8213/adfa71
Citations
3
Primary Topic
Solar and Space Plasma Dynamics
Type
article
Field-Weighted Citation Impact
3.46

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Measuring the Magnetic Field of a Coronal Mass Ejection from the Low to Middle Corona

Grégory Hellbourg, Akshatha K. Vydula, James Lamb, Mark Hodges et al.
3 citations
The Astrophysical Journal Letters
Solar and Space Plasma Dynamics
3.46
article

Measuring the Magnetic Field of a Coronal Mass Ejection from the Low to Middle Corona

Grégory Hellbourg, Akshatha K. Vydula, James Lamb, Mark Hodges, Nikita Kosogorov, Muriel Zoë Stiefel, Charlie Harnach, J. Hickish, Morgan Catha, Xingyao Chen, Kathryn Plant, Jayce Dowell, Nivedita Mahesh, Surajit Mondal, Daniel Jacobs, D. P. Woody, Vinand Prayag, Matthew Kolopanis, Gregg Hallinan, G. B. Taylor, Yuping Huang, Larry R. D’Addario, Sijie Yu, Dale E. Gary, Peijin Zhang, Ruby Byrne, Mike Virgin, Säm Krucker, Rick Hobbs, Casey Law, Marin M. Anderson, Sherry Chhabra, Ivey Davis, S. Weinreb, Judd D. Bowman, David O. Hodge, A. Romero‐Wolf, Bin Chen, Jun Shi, Brian O’Donnell, Andrea Isella, Travis Powell, Ghislain Kemby, John T. Klinefelter, Andres Rizo, Jordan Trim
article en
3 citations

Abstract

Abstract A major challenge in understanding the initiation and evolution of coronal mass ejections (CMEs) is measuring the magnetic field of the magnetic flux ropes (MFRs) that drive CMEs. Recent developments in radio imaging spectroscopy have paved the way for diagnosing the CMEs’ magnetic field using gyrosynchrotron radiation. We present magnetic field measurements of a CME associated with an X5-class flare by combining radio imaging spectroscopy data in microwaves (1–18 GHz) and meter waves (20–88 MHz), obtained by the Owens Valley Radio Observatory’s Expanded Owens Valley Solar Array (EOVSA) and Long Wavelength Array (OVRO-LWA), respectively. EOVSA observations reveal that the microwave source, observed in the low corona during the initiation phase of the eruption, outlines the bottom of the rising MFR-hosting CME bubble seen in extreme ultraviolet and expands as the bubble evolves. As the MFR erupts into the middle corona and appears as a white-light CME, its meter-wave counterpart, observed by OVRO-LWA, displays a similar morphology. For the first time, using gyrosynchrotron spectral diagnostics, we obtain magnetic field measurements of the erupting MFR in both the low and middle corona, corresponding to coronal heights of 0.02 and 1.83 R ⊙ . The magnetic field strength is found to be around 300 G at 0.02 R ⊙ during the CME initiation and about 0.6 G near the leading edge of the CME when it propagates to 1.83 R ⊙ . These results provide critical new insights into the magnetic structure of the CME and its evolution during the early stages of its eruption.

The Astrophysical Journal LettersVol. 990(2)
New Jersey Institute of Technology (US), California Institute of Technology (US), Jet Propulsion Laboratory (US), George Mason University (US), University of New Mexico (US), University Corporation for Atmospheric Research (US), FHNW University of Applied Sciences and Arts Northwestern Switzerland (CH), ETH Zurich (CH), Cobham (United Kingdom) (GB), Arizona State University (US), Rice University (US), Bournemouth University (GB), University of California, Berkeley (US)
National Aeronautics and Space Administration
Openalex Percentile: Top 7%
Solar and Space Plasma Dynamics
3.46
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.