{
  "submitter": "J.-G. Ducoin at CPPM <ducoin@cppm.in2p3.fr>",
  "eventId": "GRB 260915A",
  "body": "Jean-Grégoire Ducoin (CPPM), William H. Lee (UNAM), Stéphane Basa (UAR Pytheas), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Dalya Akl (NYUAD), Sarah Antier (IJCLAB), Rosa L. Becerra (UNAM), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Francis Fortin (IRAP),  Leonardo García-García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Marion Guelfand (CPPM), Asuka Kuwata (UNAM), Massimiliano Lincetto (CPPM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM),  Alan M. Watson (UNAM), Y. F. Liang(PMO), C. Plasse (HKU), report:\n\nWe imaged the field of the SVOM GRB 260915A (Liang et al., GCN Circ. 45570) using the DDRAGO wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2026-09-15T05:23:02 to 05:42:23 UTC (from 4.14 to 4.46 hours after the trigger) and obtained 16 minutes of simultaneous exposure in the r and z filters.\n\nThe data were reduced, coadded and analysed with the COLIBRÍ pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR2 catalog, is in the AB system, and is not corrected for Galactic extinction.\n\nIn the stacked image, we do not detect any new source at the MXT source position (Liang et al., GCN Circ. 45570) down to the following 5-sigma limit:\n\nr > 23.12\nz > 21.76\n\nThis upper limit is consistent with the one reported by Zhu et al. GCN Circ. 45577 and by Perez-Garcia et al. GCN Circ. 45578.\n\nWe thank the staff of the Observatorio Astronómico Nacional at Sierra de San Pedro Mártir, as well as the technical and engineering teams at CEA, CPPM, IRAP, LAM, OHP, OSU Pytheas, and UNAM.\n\nCOLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico.\n",
  "eventType": [
    "GRB",
    "X-ray Transient"
  ],
  "subject": "GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit",
  "submittedHow": "web",
  "createdOn": 1789462446078,
  "format": "text/plain",
  "circularId": 45580
}