Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

GCN Circular 42080

Subject
GRB 251002A: SVOM/COLIBRÍ (FM-GFT) optical observations
Date
2025-10-03T08:37:03Z (5 days ago)
From
Benjamin Schneider at MIT <bschn@mit.edu>
Via
Web form
Benjamin Schneider (LAM), Enrique Moreno Méndez (UNAM), Camila Angulo (UNAM), Ny Avo Rakotondrainibe (LAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Alan M. Watson (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (NYUAD), Sarah Antier (OCA), Rosa L. Becerra (U Roma), Nathaniel R. Butler (ASU) , Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Margarita Pereyra (UNAM), Fredd Sánchez Álvarez (UNAM), Antonio de Ugarte Postigo (LAM), Andrea Saccardi (CEA/Irfu), and Diego Gotz (CEA/Irfu):

We imaged the field of the SVOM GRB 251002A (Saccardi et al., GCN Circ. 42060) using the DDRAGO wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2025-10-03 03:33:53 to 05:48:35 UTC (from 7.32 to 9.56 hr after the trigger) and obtained 16 minutes of exposure in the g, r, i, z and y filters.

The data were reduced and coadded with the COLIBRÍ pipeline and analyzed with STDWeb/STDPipe (Karpov 2025). The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction.

We detected the optical counterpart reported by Palmerio et al., GCN Circ. 42061, Turpin et al., GCN Circ. 42062; Jelinek et al., GCN Circ. 42063; Juliá-Maroto et al. GCN Circ. 42064; Moskvitin et al. GCN Circ. 42065; Perez-Garcia et al. GCN Circ. 42066; Senik et al., GCN Circ. 42067; Saccardi et al., GCN Circ. 42076; Mandarakas et al., GCN Circ. 42077; Cao et al, GCN 42078 at preliminary magnitudes of:

g = 20.96 +/- 0.09 (mid-time 8.41 hr)
r = 20.82 +/- 0.07 (mid-time 8.44 hr)
i = 20.64 +/- 0.07 (mid-time 8.46 hr)
z = 20.76 +/- 0.15 (mid-time 8.42 hr)
y = 20.30 +/- 0.22 (mid-time 7.84 hr)

Further observations and analysis are ongoing in g, r, i, z and y filters.

We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams.

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.
Looking for U.S. government information and services? Visit USA.gov