Starspots as the origin of ultrafast drifting radio bursts from an active M dwarf
Detecting coherent radio bursts from nearby M dwarfs provides opportunities for exploring their magnetic activity and interaction with orbiting exoplanets. However, it remains uncertain whether the emission is related to flare-like activity similar to the Sun or magnetospheric process akin to magnetized planets. Using observations (1.0 to 1.5 gigahertz) taken by the Five-hundred-meter Aperture Spherical radio Telescope, we found a type of millisecond-scale radio bursts with exceptionally high-frequency drift rates (~8 gigahertz per second) from an active M dwarf, AD Leo. The ultrafast drift rates point to a source region with a notably low magnetic scale height (<0.15 [Formula: see text] , [Formula: see text] as the stellar radius), a feature not expected in a commonly assumed dipole-like global field but highly possible in localized strong-field structures, i.e., starspots. Our findings suggest that a concentrated magnetic field above starspots could be responsible for some of the most intense radio bursts from M dwarfs, supporting a solar-like electron acceleration mechanism.
Authors
- Hui Tian (ORCID: https://orcid.org/0000-0002-1369-1758)
- J. R. Callingham (ORCID: https://orcid.org/0000-0002-7167-1819)
- H. K. Vedantham (ORCID: https://orcid.org/0000-0002-0872-181X)
- Jinghai Sun (ORCID: https://orcid.org/0000-0002-8123-8293)
- Chunwen Sun (ORCID: https://orcid.org/0000-0002-3610-9396)
- Sijie Yu (ORCID: https://orcid.org/0000-0003-2872-2614)
- Meng-Lin Huang (ORCID: https://orcid.org/0000-0002-3050-5400)
- Tianqi Cang (ORCID: https://orcid.org/0000-0003-3816-7335)
- S. Bellotti (ORCID: https://orcid.org/0000-0002-2558-6920)
- P. Zarka (ORCID: https://orcid.org/0000-0003-1672-9878)
- Lei Zheng (ORCID: https://orcid.org/0000-0002-6452-4124)
- Corentin Louis (ORCID: https://orcid.org/0000-0002-9552-8822)
- Jiale Zhang (ORCID: https://orcid.org/0009-0004-0713-405X)
- Bin Chen
- Yang Gao (ORCID: https://orcid.org/0000-0002-6316-1632)
- Hui Li (ORCID: https://orcid.org/0000-0002-3885-6125)
- Peng Jiang (ORCID: https://orcid.org/0009-0003-3527-8520)
- H. Lu (ORCID: https://orcid.org/0000-0002-7259-5897)
- Hengqian Gan (ORCID: https://orcid.org/0000-0003-0556-1045)
Institutions
- New Jersey Institute of Technology (US)
- Leiden University (NL)
- Université d'Orléans (FR)
- Centre National de la Recherche Scientifique (FR)
- Sun Yat-sen University (CN)
- University of Groningen (NL)
- Guizhou University (CN)
- Université Fédérale de Toulouse Midi-Pyrénées (FR)
- Chinese Academy of Sciences (CN)
- Peking University (CN)
- Université Paris Cité (FR)
- Beijing Normal University (CN)
- Observatoire de Paris (FR)
- Sorbonne Université (FR)
- Sorbonne Paris Cité (FR)
- AstroTec Holding (Netherlands) (NL)
- National Space Science Center (CN)
- National Astronomical Observatories (CN)
- Institut de Recherche en Astrophysique et Planétologie (FR)
- Netherlands Institute for Radio Astronomy (NL)
Publication Details
- Journal
- Science Advances
- Published
- 2025-10-17
- DOI
- https://doi.org/10.1126/sciadv.adw6116
- Citations
- 2
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 2.31