GCN Circular 45564
Subject
GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
Event
Date
2026-09-14T13:58:55Z (4 days ago)
From
J.-G. Ducoin at CPPM <ducoin@cppm.in2p3.fr>
Via
Web form
Dalya Akl (NYUAD), Fredd Sánchez Álvarez (UNAM), Jean-Grégoire Ducoin (CPPM), Noémie Globus (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), 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), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM), Alan M. Watson (UNAM) and Damien Turpin (CEA/Irfu) report:
We imaged the field of the SVOM GRB 260914A (Wang et al., GCN Circ. 45562) using the DDRAGO two-channel wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2026-09-14 11:14:09 to 12:03:42 UTC (from 1.4 to 51 minutes after the trigger) and obtained 43 minutes of simultaneous exposure in the r and z filters.
The data were reduced, coadded, and analysed with the COLIBRÍ and ASU pipelines. The photometry was calibrated using nearby stars from the PanSTARRS DR2 catalog, is in the AB system, and is not corrected for Galactic extinction.
In the stacked image, we tentatively detected a source revealed by image subtraction against Pan Starrs and Legacy Survey in both bands, consistent with the SVOM/ECLAIRs error circle at:
RA (J2000) = 02:06:23.78 = 31.5991 deg
Dec (J2000) = +29:15:17.5 = 29.2549 deg
with an estimated astrometric uncertainty of 0.5 arcsec.
The preliminary magnitude derived for that source after subtraction is:
r = 20.14 ± 0.04
z = 19.66 ± 0.04
We encourage additional observations to confirm the nature of the source.
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.