{
  "body": "H. Yang, O. Godet, S. Guillot (IRAP), D. Turpin (CEA) \n\nreport on behalf of the SVOM team:\n\nThe SVOM/ECLAIRs telescope detected GRB 250607A, also detected by Fermi/GBM (GCN 40648) and SVOM/GRM (GCN 40651), starting at 2025-06-07T14:00:51 UTC (T0), through an offline targeted search with the event-by-event data downloaded via the X-band ground station.\n\nThe burst was detected within several timescales and energy ranges. The best detection is obtained by the image trigger with a signal-to-noise ratio of 7.4 within 4-20 keV over a time window of 10 s starting at T0. This event was not detected onboard because it was too faint and near the edge of the field of view.\n\nThe ECLAIRs lightcurve shows a multi-peaked structure lasting around 10 s, with most of the detected photons below 50 keV. \n\nThe localization of the source is RA, Dec = 228.408, -19.894 degrees:\n\nRA (J2000) = 15h13m38s\nDec (J2000) = -19d53m38s\n\nwith a 90% C.L. radius of 10.8 arcmin (including systematic error of 2 arcmin added in quadrature). This localization is broadly consistent with that reported by Fermi/GBM (GCN 40648). The angular separation between the two positions is 15 degrees, which is compatible with the 10.15 degrees statistical uncertainty of the GBM localization. \n\nThe time-averaged spectrum from T0 to T0+10 s in the 5-120 keV is well fitted by a power law with a photon index of 1.6+/-0.2 and a corresponding 4-120 keV fluence of (1.2+/-0.3)e-6 erg/cm^2. The spectral properties measured with SVOM/ECLAIRs are consistent with those reported by SVOM/GRM (GCN 40651). \n\nAll quoted errors are at the 68% confidence level.\n\nThe 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. \n\nThe SVOM/ECLAIRs point of contact for this event is : Hui Yang (hui.yang@cnrs.fr) ",
  "circularId": 45351,
  "eventId": "GRB 250607A",
  "bibcode": "2026GCN.45351....1Y",
  "subject": "GRB 250607A: SVOM/ECLAIRs detection through offline targeted search",
  "editedOn": 1786455586359,
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "createdOn": 1786393382329,
  "eventType": [
    "GRB",
    "X-ray Transient"
  ],
  "format": "text/plain",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of SVOM_group <svomgroup@bao.ac.cn>",
  "version": 2,
  "submittedHow": "web"
}