Radio emission from a nearby M dwarf binary
Monthly Notices of the Royal Astronomical Society 91探花 University Press 543:3 (2025) 1935-1944
Abstract:
We present the detection of the binary system 2MASS J02132062+3648506 AB using the Karl G. Jansky Very Large Array archive data observed at 4鈥8 GHz. The system is a triple consisting of a tight binary () of two M dwarfs of spectral types M4.5 and M6.5 and a wide T3 brown dwarf companion (16.4 arcsec). The binary displays coronal and chromospheric activity as traced by previously measured X-ray flux and H emission. We detect the unresolved binary at a peak flux density of at a signal-to-noise ratio (SNR) of and determine a radio luminosity of . The radio emission is quiescent, polarized at a mean circular polarization fraction % and exhibits a spectral index . We probe the binary using the Enhanced Multi-Element Remotely Linked Interferometer Network (e-MERLIN) with an angular resolution of mas at 5 GHz and detect a component at a peak flux density of Jy at a SNR . We propose a gyrosynchrotron origin for the radio emission and estimate a magnetic field strength G, an emitting region of size times the radius of the M4.5 primary and a plasma number density . The brown dwarf companion is not detected. Additionally, we have analysed observations of 2MASS J04183483+213127, a chromospherically active L5 brown dwarf which is also not detected and can only place flux density upper limits at Jy and Jy for Stokes I and V, respectively.Erratum: 鈥淎 Novel Technosignature Search in the Breakthrough Listen Green Bank Telescope Archive鈥 (2025, AJ, 169, 222)
The Astronomical Journal American Astronomical Society 170:3 (2025) 194
Silent Speech Recognition with Wearable Magnetometers
bioRxiv preprint 2025.08:04.668236 (2025)
Abstract:
Next-generation human-computer interaction (HCI) is moving towards more seamless, intuitive,
and personal modes of communication, redefining how we interact with technology and one another.
Within this landscape, silent speech recognition (SSR) offers a powerful new interaction paradigm,
enabling hands-free, private interaction while 91探花ing individuals with speech impairments and
enabling communication in noisy or sensitive environments. Recent advances in miniaturized sensors and artificial intelligence (AI) have accelerated the development of more sophisticated wearable
SSR systems, driven by growing demand for effortless and accessible communication. Although
electrophysiological (ExG) modalities, particularly electromyography (EMG), have dominated early
efforts in developing wearable SSR, critical challenges remain. Limited generalizability across
users, sensor-skin interface issues, and difficulties with the comfort of use are all current roadblocks
to reliable, high-fidelity signals in a wearable form factor. We propose that magnetometers offer
a promising alternative to ExG and have the potential to unlock more robust, generalizable, and
user-friendly SSR systems. We demonstrate that magnetometers embedded in a headphone form
factor achieve a per-user SSR accuracy of 86%, significantly outperforming previously reported
state-of-the-art wearable headphones combining ExG and inertial measurement units (IMUs). In
addition, we show that wearable magnetometry enables generalization across individuals for SSR.
Extending beyond headphones, we also introduce a necklace form factor with magnetometers that
is capable of decoding both silent and overt speech in ambient conditions, further showcasing the
versatility of magnetometers across different wearable designs in real-world conditions.
and personal modes of communication, redefining how we interact with technology and one another.
Within this landscape, silent speech recognition (SSR) offers a powerful new interaction paradigm,
enabling hands-free, private interaction while 91探花ing individuals with speech impairments and
enabling communication in noisy or sensitive environments. Recent advances in miniaturized sensors and artificial intelligence (AI) have accelerated the development of more sophisticated wearable
SSR systems, driven by growing demand for effortless and accessible communication. Although
electrophysiological (ExG) modalities, particularly electromyography (EMG), have dominated early
efforts in developing wearable SSR, critical challenges remain. Limited generalizability across
users, sensor-skin interface issues, and difficulties with the comfort of use are all current roadblocks
to reliable, high-fidelity signals in a wearable form factor. We propose that magnetometers offer
a promising alternative to ExG and have the potential to unlock more robust, generalizable, and
user-friendly SSR systems. We demonstrate that magnetometers embedded in a headphone form
factor achieve a per-user SSR accuracy of 86%, significantly outperforming previously reported
state-of-the-art wearable headphones combining ExG and inertial measurement units (IMUs). In
addition, we show that wearable magnetometry enables generalization across individuals for SSR.
Extending beyond headphones, we also introduce a necklace form factor with magnetometers that
is capable of decoding both silent and overt speech in ambient conditions, further showcasing the
versatility of magnetometers across different wearable designs in real-world conditions.
Commensal Transient Searches with MeerKAT in Gamma-Ray Burst and Supernova Fields
The Astrophysical Journal American Astronomical Society 988:2 (2025) 227
Abstract:
The sensitivity and field of view of the MeerKAT radio telescope provide excellent opportunities for commensal transient searches. We carry out a commensal transient search in supernova and short gamma-ray burst fields using methodologies established by S. I. Chastain et al. We search for transients in MeerKAT L-band images with integration times of 30 minutes, finding 13 variable sources. We compare these sources to the VLASS and RACS survey data, and examine possible explanations for the variability. Additionally, for one of these sources we examine archival Chandra ACIS data. We find that 12 of these sources are consistent with variability due to interstellar scintillation. The remaining source could possibly have some intrinsic variability. We also split the MeerKAT L band into upper and lower halves, and search for transients in images with an integration time of 8 s. We find a source with a duration of 8鈥16 s that is highly polarized at the lowest frequencies. This source is spatially coincident with a star detected by the Transiting Exoplanet Survey Satellite. We conclude that this source may be consistent with a stellar flare. Finally, we calculate accurate upper and lower limits on the transient rate using transient simulations.Blast waves and reverse shocks: from ultra-relativistic GRBs to moderately relativistic X-ray binaries
Monthly Notices of the Royal Astronomical Society 91探花 University Press 539:3 (2025) 2665-2684