{
  "submittedHow": "web",
  "submitter": "globus@astro.unam.mx",
  "eventType": [
    "X-ray Transient"
  ],
  "circularId": 45801,
  "body": "Noémie Globus (UNAM), Jean-Grégoire Ducoin (CPPM), Camila Angulo (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), 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), 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) report:\n\nWe imaged the field of the EP261003a (Lao et al., GCN Circ. 45798) using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. We observed from 2026-10-03 03:41:26 to 04:47:19 UTC (from 3.45 to 4.56 hours after the trigger) and obtained 51 minutes of simultaneous exposure in the r and z filters.\n\nThe data were reduced and analyzed with the COLIBRÍ ASU pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR1 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 FXT source position down to the following 5-sigma limit:\n\nr > 23.88,\nz > 22.40.\n\nFurther observations are ongoing.\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.",
  "createdOn": 1791003854122,
  "format": "text/plain",
  "subject": "EP261003a: COLIBRÍ optical upper limits",
  "eventId": "EP261003a"
}