TITLE: GCN CIRCULAR NUMBER: 45227 SUBJECT: EP260723a: SVOM/ECLAIRs Upper Limit DATE: 26/07/27 13:44:17 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> H. Yang, M. Brunet, O. Godet, S. Guillot (IRAP) report on behalf of the SVOM team: We performed a targeted search of the X-ray transient EP260723a, detected by EP-WXT at 2026-07-23T18:56:01 UTC (T0) with a duration of about 100 s (EP team, GCN 45201), using the SVOM/ECLAIRs event-by-event data downloaded through the X-band ground station. At T0, the transient position was within the ECLAIRs field of view. No statistically significant signal was identified in the [T0 - 500 s, T0 + 3000 s] interval by the ECLAIRs image trigger performed on multiple timescales and energy bands. For the interval from T0 to T0 + 100 s, we derive a 3-sigma upper limit of 2.4e-9 erg/cm^2/s in the 4-120 keV energy band, assuming a power-law spectrum with a photon index of 1.4, as measured by EP-WXT (GCN 45201). Alternatively, assuming a “soft” spectral template (a Band function with Epeak = 25 keV, alpha = -1.5, beta = -3.0), we derive a 3-sigma upper limit of 1.5e-9 erg/cm^2/s. The Space 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 APC, CEA, CNES, and IRAP. The SVOM/ECLAIRs point of contact for this event is : Hui Yang (hui.yang@cnrs.fr) View this GCN Circular online at https://gcn.nasa.gov/circulars/45227. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...