TITLE: GCN CIRCULAR NUMBER: 46137 SUBJECT: GRB 261103A: SVOM/ECLAIRs detection of a burst through on-ground search DATE: 26/11/03 11:24:02 GMT FROM: SVOM_group M. Brunet (IRAP), Y.-H.Cheng (YNU), W.-L.Zhang (PMO) report on behalf of the SVOM/ECLAIRs team The SVOM/ECLAIRs telescope detected a transient source, labelled GRB 261103A, starting at 2026-11-03T06:51:11 UTC (trigger time T0), through an on-ground search with the event-by-event data downloaded through the X-band ground station. The burst was detected within several energy ranges and timescales. The best detection is obtained by the Image Trigger with a signal-to-noise ratio of 7.1 within 4-20 keV over a time window of 40.96 seconds starting at T0-40.96s. The burst that triggered ECLAIRs onground shows a single peak lightcurve. The localization of the source is RA, Dec = 14.157, 18.701 degrees: RA (J2000) = 00h56m37.7s Dec (J2000) = 18d42m03.6s with a 90% C.L. radius of 11.04 arcmin (including systematic error of 2 arcmin added in quadrature). We note that no bright catalogued X-ray sources are found in the error box All the quoted errors are at the 68% confidence level. The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. The Burst Advocate (BA) on shift for this alert is Y.-H.Cheng (yhcheng@mail.ynu.edu.cn) Please contact the BA by email if you require additional information.