GCN Circular 41054
Subject
GRB 250702B,D,E/EP250702A: MeerKAT radio observations at 1.28GHz
Event
Date
2025-07-09T22:26:57Z (3 days ago)
From
lauren.rhodes@mcgill.ca
Via
Web form
Pikky Atri (Astron), Lauren Rhodes (TSI/McGill), Rob Fender (Oxford), Andrew Hughes (Oxford),and Sara Motta (INAF-OAB) report on behalf of the XKAT Collaboration.
The MeerKAT radio telescope observed the position of GRB 250702B,D,E/EP250702A (GCNs 40906, 40883, 40885, 40886, 40890, 40891) as part of the XKAT program on 06-07-2025 starting at 18:53:41 UT for 15 minutes. The observation was made at a central frequency of 1.28GHz with a bandwidth of 856MHz. We detect a point source with a flux density of ~100uJy at the coordinates R.A.: 18:58:45.5, Dec: -07:52:28.2 with a positional uncertainty of ~1" (please note the slight offset in declination).
The proximity of EP250702a on the sky to the neutron star X-ray Swift J1858.6-0814 allowed us to check archival observations from MeerKAT of the new transient’s position. Using our most recent observation of the Swift J1858.6-0814 from 02-03-2020 (Rhodes et al 2020), we place a 3-sigma upper limit of 114uJy/beam at the position of the EP250702a.
Further observations are planned.
We thank the SARAO staff for rapidly scheduling these observations. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.
X-KAT is a large MeerKAT open-time programme to observe X-ray binaries in the radio band, performing weekly monitoring of bright, active systems, with capacity for higher cadence observations, and in coordination with large X-ray and optical monitoring programmes. For further information on this programme contact Rob Fender.