Discovery of a radio-flaring M dwarf in a commensal transient search of the LADUMA field

We report the discovery and characterization of MKT J032848.4–271904.6, a new radio transient identified in the LADUMA field using SARAO Science Data Processor SDP UHF-band images from approximately 1 yr of MeerKAT observations. Using the Transient Pipeline TraP and advanced filtering techniques, we identified a number of candidate variable radio sources in the field. All but one show variability consistent with refractive interstellar scintillation, leaving MKT J032848.4–271904.6 as the sole source exhibiting intrinsic variability. In addition, MKT J032848.4–271904.6 shows intrinsic variability at 0.816 GHz, with 13 radio detections across 41 epochs and a peak flux density of 1.041 (Formula presented) 0.043 mJy. We associate this emission with a low-mass M-dwarf star LP 888–63, located 23 pc from the Sun and identified as a companion to the white dwarf binary system LAWD 14 WD 0326–273. LP 888–63 displays active flaring behaviour across the electromagnetic spectrum including multiband optical data from MeerLICHT. TESS photometry reveals a periodic modulation in the blended light curve of 5.780 (Formula presented) 0.507 d, consistent with rotational variability of a mid-M dwarf. Archival ESO spectra reveal H (Formula presented) emission, confirming magnetic activity. These findings highlight the capability of MeerKAT’s SDP imaging and facilities like MeerLICHT for real-time detection and characterization of stellar transients.