MeerKAT discovery of a new repeating fast radio burst FRB 20251130A

ATel #17548; Jun Tian (University of Manchester), Ines Pastor-Marazuela (ASTRON), Kavya Shaji (University of Sydney), Ben Stappers (University of Manchester), Manisha Caleb (University of Sydney), Kaustubh Rajwade (University of Oxford), Alexa Gordon (Northwestern University), Wen-Fai Fong (Northwestern University), Fabian Jankowski (Universite d'Orleans), Mayuresh Surnis (IISER Bhopal), Ewan Barr (MPIfR), on behalf of the MeerTRAP team
on 18 Dec 2025; 08:43 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Jun Tian (jun.tian@manchester.ac.uk)

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The MeerTRAP team reports the discovery of a new repeating FRB source, FRB 20251130A. We detected one burst on 2025 November 30, followed by three bursts on 2025 December 3. These bursts were detected in the incoherent beam of MeerKAT and triggered storage of channelised voltage data from the individual MeerKAT antennas, which we used to initially localise the FRB in the image domain using our transient buffer imaging pipeline (Rajwade et al. 2024; also see Rajwade et al. 2020). Using the triggered data of the fourth burst, we localised the FRB to the coordinates RA = 10:33:53.45, Dec = -27:53:30.29 with a 1-sigma uncertainty of 0.36 arcsec and 0.51 arcsec in RA and Dec, respectively, roughly 42 arcmin away from the phase centre of the observation. The localisation of the burst can be seen in the link below. A preliminary analysis of the voltage data shows that the brightest burst has a Faraday rotation measure of ~23 rad/m^2. The dynamic spectra of the four bursts are displayed following the link attached, and the burst properties measured from the incoherent beam detections are listed below:

Burst ToA (topocentric) DM (pc cm^-3) S/N Fluence (Jy ms)
1 2025-11-30 00:15:29.718 976.4 14.88 27.2
2 2025-12-03 00:26:40.082 977.4 25.72 33.7
3 2025-12-03 05:01:08.800 978.8 15.30 20.0
4 2025-12-03 05:03:04.363 976.0 14.97 19.6

Given the limited sensitivity of the MeerKAT incoherent beam, the inferred burst fluences, and the total observing time at the FRB coordinates (~9 hours), the burst activity could be as high as >200 bursts hr^-1 at a fluence limit of 1 Jy ms. We carried out a 3h follow-up observation of FRB 20251130A with MeerKAT, 1h at UHF (544-1088 MHz), 1h at L-band (856 - 1712 MHz) and 1h at S-band (1750 - 2625MHz), on 2025 December 12 at 22:28 UTC under the project ID: SCI-20251103-IP-01. Despite the increased MeerKAT sensitivity achieved by placing the FRB near the phase centre, we detected only two bursts at UHF and one at L-band, suggesting either a rapid decrease in activity or strong temporal clustering of bursts.

We identified a galaxy in the DESI Legacy Survey DR10 source catalogue (Dey et al. 2019), 0.91 arcsec away from the FRB location, with a probability of association of 99.48% (PATH, Aggarwal et al. 2021). The galaxy is located at RA = 10:33:53.47, DEC = -27:53:31.15, it has a catalogued r-band magnitude of 20.67 AB, and photometric redshift of 0.41+0.12-0.10 (95% confidence). Given that the Galactic contribution to the DM is ~60 pc cm^-3 (YMW16 model), the photometric redshift would imply a large local contribution to the observed DM, of up to 500 pc cm^-3 in the observer's frame, or ~700 pc cm^-3 in the host galaxy frame. However, a spectroscopic redshift is necessary to confirm this conclusion.

We would like to thank the Director and the operators of MeerKAT and the South African Radio Astronomy Observatory (SARAO) for the prompt scheduling of the observation. The MeerKAT telescope is operated by SARAO, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.

Dynamic spectra and localisation of FRB 20251130A