Starspots as the origin of ultrafast drifting radio bursts from an active M dwarf
arXiv:2510.17547 · doi:10.1126/sciadv.adw6116
Abstract
Detecting coherent radio bursts from nearby M dwarfs provides opportunities for exploring their magnetic activity and interaction with orbiting exoplanets. However, it remains uncertain if the emission is related to flare-like activity similar to the Sun or magnetospheric process akin to magnetized planets. Using observations (1.0 - 1.5 GHz) 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 () from an active M dwarf, AD Leo. The ultrafast drift rates point to a source region with a notably low magnetic scale height (, 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.
arXiv commentPublished on Science Advances, the authors' version
References in corpus (63)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- Array Programming with NumPy
- The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
- A bright millisecond radio burst of extragalactic origin
- The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
- How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
- The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m Program -- Twenty New Members of the RECONS 10 Parsec Sample
- The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
- Large-scale magnetic topologies of mid-M dwarfs
- A Review of Solar Type III Radio Bursts
- The Fundamental Performance of FAST with 19-beam Receiver at L Band
- Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
- M-dwarf stellar winds: the effects of realistic magnetic geometry on rotational evolution and planets
- Magnetospherically driven optical and radio aurorae at the end of the stellar main sequence
- Particle Acceleration by a Solar Flare Termination Shock
- PSRCHIVE and PSRFITS: Definition of the Stokes Parameters and Instrumental Basis Conventions
- Measurement of magnetic field and relativistic electrons along a solar flare current sheet
- Coherent radio emission from a quiescent red dwarf indicative of star-planet interaction
- Magnetic fields of M dwarfs
- Explaining the coexistence of large-scale and small-scale magnetic fields in fully convective stars
- On the magnetic topology of partially and fully convective stars
- Strong dipole magnetic fields in fast rotating fully convective stars
- Ultra-Wideband Detection of 22 Coherent Radio Bursts on M Dwarfs
- No Sun-like dynamo on the active star Andromedae from starspot asymmetry
- Circular polarization in pulsar integrated profiles
- The population of M dwarfs observed at low radio frequencies
- A Flare-Type IV Burst Event from Proxima Centauri and Implications for Space Weather
- Origin of electron cyclotron maser-induced radio emissions at ultra-cool dwarfs: magnetosphere-ionosphere coupling currents
- Ultra-high-time Resolution Observations of Radio Bursts on AD Leonis
- Optical and X-ray observations of stellar flares on an active M dwarf AD Leonis with Seimei Telescope, SCAT, NICER and OISTER
- Coherent radio bursts from known M-dwarf planet host YZ Ceti
- Wideband Spectroscopy of Two Radio Bursts on AD Leonis
- MOST Observations of the Flare Star AD Leo
- Magnetic cycles in a dynamo simulation of fully convective M-star Proxima Centauri
- The GAPS Programme at TNG XXI -- A GIARPS case-study of known young planetary candidates: confirmation of HD 285507 b and refutation of AD Leo b
- Structure and evolution of low-mass stars
- Formation of starspots in self-consistent global dynamo models: Polar spots on cool stars
- The magnetic field vector of the Sun-as-a-star
- Exploring the magnetic field complexity in M dwarfs at the boundary to full convection
- Unsigned magnetic flux as a proxy for radial-velocity variations in Sun-like stars
- Low-frequency monitoring of flare star binary CR Draconis: Long-term electron-cyclotron maser emission
- Influence of surface stressing on stellar coronae and winds
- A sudden change of the global magnetic field of the active M dwarf AD Leo revealed by full Stokes spectropolarimetric observations
- Constraining atmospheric parameters and surface magnetic fields with : an application to SPIRou spectra
- V-LoTSS: The Circularly-Polarised LOFAR Two-metre Sky Survey
- How good is the bipolar approximation of active regions for surface flux transport?
- The CARMENES search for exoplanets around M dwarfs: Stable radial-velocity variations at the rotation period of AD~Leonis -- A test case study of current limitations to treating stellar activity
- K2 Ultracool Dwarfs Survey. V. High superflare rates on rapidly rotating late-M dwarfs
- Monitoring the large-scale magnetic field of AD~Leo with SPIRou, ESPaDOnS and Narval. Toward a magnetic polarity reversal?
- Torus-Stable Zone Above Starspots
- Auroral Radio Emission from Ultracool Dwarfs: a Jovian Model
- AD Leonis: Radial velocity signal of stellar rotation or spin-orbit resonance?
- Fine structures of radio bursts from flare star AD Leo with FAST observations
- Complexity of magnetic fields on red dwarfs
- X-ray spectroscopy of the unsteady quiescent corona of AD Leo with Chandra
- The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations
- Energetic particle activity in AD Leo: Detection of a solar-like type-IV burst
- On the mechanism of polarised metrewave stellar emission
- MHD study of planetary magnetospheric response during extreme solar wind conditions: Earth and exoplanet magnetospheres applications
- Source of radio emissions induced by the Galilean moons Io, Europa and Ganymede: in situ measurements by Juno
- Photometric observations of flares on AD Leo from GWAC-F30 and TESS
- The milliarcsecond-scale radio structure of AB Dor A
- Location and energy of electrons producing the radio bursts from AD Leo observed by FAST in December 2021