GCN Circular 45341
Subject
GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
Event
Date
2026-08-10T09:37:48Z (16 hours ago)
From
Stephane Basa at UAR Pytheas/OHP, LAM <stephane.basa@lam.fr>
Via
Web form
Stéphane Basa (UAR Pytheas), Noémie Globus (UNAM), William H. Lee (UNAM), 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), Jean-Grégoire Ducoin (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) and Michela Maria Dinatolo (U. Milano) report:
We imaged the field of the SVOM GRB 260808B (Bouchet et al., GCN 45316) using the DDRAGO wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2026-08-10 07:02:08 to 08:48:29 UTC (from 40.6 to 42.4 hours after the trigger) and obtained 48x60 seconds of exposure in the z band.
The data were reduced, coadded and analyzed with the ASU and CPPM COLIBRÍ pipelines. The photometry was calibrated using nearby stars from the PanSTARRS DR1r catalog, is in the AB system, and is not corrected for Galactic extinction.
In the stacked image, we detect the optical counterpart (Turpin et al., GCN 45318; Li et al., GCN 45320; Saccardi et al., GCN 45328; Schneider et al., GCN 45329; Bochenek et al., GCN 45330) at a preliminary magnitude of:
z = 22.21 +/- 0.08
Further observations are ongoing.
We 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.
COLIBRÍ 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.