{
  "editedOn": 1778593364389,
  "format": "text/plain",
  "eventId": "GRB 260511A",
  "createdOn": 1778481469168,
  "body": "O. Godet, M. Brunet (IRAP), L. Zhang (IHEP), D. Kong (GXU) report on behalf of the SVOM mission team:\n\nAt 2026-05-11T06:13:32 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260511A (SVOM burst-id sb26051101).\n\nThis transient was also detected by Fermi/GM (GCN Circular 44529).\n\nThe following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.\n\nThe burst was detected both by the Count-Rate Trigger (CRT) and the Image Trigger (IMT), which produced a sequence of 16 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 55.22 in the [8-120] keV energy band over a time window of 10.20 seconds starting at 2026-05-11T06:13:32.\n\nThe localization of the best alert is R.A., Dec. 197.929, -33.853 degrees (J2000) with a 90% confidence level (C.L.) radius of 2.44 arcmin (including systematic error of 2 arcmin added in quadrature).\n\nThe SVOM/ECLAIRs light curve showed a multiple peak structure with a T90 duration of 13.5 (-0.4/ +0.6) s in the 5-120 keV.\n\nThis burst also triggered SVOM/GRM at 2026-05-11T06:13:30 on a timescale of 1 seconds with an SNR of 12.10.\n\nThe SVOM/GRM light curve showed a multiple peak structure with a T90 duration of 14.3 (-0.4 / +0.8) s in the 8-1100 keV.\n\nSVOM slewed to the burst.\n\nSVOM/MXT began observing the field at 2026-05-11T06:16:38 UTC, 186 seconds after T0. Using onboard processed data we found an uncatalogued X-ray source located at R.A., Dec. 197.9145, -33.8120 degrees:\nR.A. (J2000) = 13h11m39.48s\nDec. (J2000) = -33d48m43.09s\nwith a 90% C.L. radius of 39.05 arcseconds.\n\nThis location is 2.54 arcminutes from the ECLAIRs onboard position. This position may be improved as more data is received.\n\nVT began observing the field after the slew. The analysis of the data will be published in a future circular.\n\nThe 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. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE.\n\nThe Burst Advocate (BA) on shift for this alert is zhangli: zhangli at ihep.ac.cn\nPlease contact the BA by email if you require additional information.",
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "subject": "GRB 260511A: SVOM detection of a bright burst",
  "submittedHow": "web",
  "bibcode": "2026GCN.44532....1G",
  "circularId": 44532,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of SVOM_group <svomgroup@bao.ac.cn>",
  "version": 3
}