GCN Circular 45717
GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
From: Alberto Castro-Tirado at Inst.de Astro. de Andalucia
Issued: 2026-09-24 07:10 UTC
Y.-D. Hu (GXI), A. Sota, E. Fernandez-Garcia, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia and M. Gritsevich (IAA-CSIC), on behalf of a larger collaboration, report:
Following the detection of GRB 260924A by both Fermi (Fermi team, GCN 45712) and Swift (D'Elia et al. GCN 45713), we triggered the 1.5m telescope at Sierra Nevada Observatory (OSN) in Granada (Spain), starting on Sep 24, 04:24 UT (~3.18 h post trigger) in the BVRI filters. An uncatalogued object is detected within the XRT error circle (Evans et al. GCNC 45715) with R=15.5+-0.1 mag (calibrated with USNO B2), which we propose to be the GRB 260924A optical afterglow. Spectroscopic observations are encouraged.
We thank the staff at OSN for their excellent support.
Filter: gamma-ray bursts are posted only if in the top 10% of the past year's — by fluence (total energy received per cm², from Fermi GBM, Konus-Wind, GECAM and similar circulars; now ≥ 3.9×10^-5 erg/cm²) or by the number of GCN Circulars about the burst (now ≥ 14). Thresholds are recalculated monthly.
Relayed automatically from NASA's General Coordinates Network.
Transient Alerts » in reply to GRB 260924A
GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
The whole thread (28 posts)
- GRB 260924A
- GRB 260924A: VLA detection
- GRB 260924A: Swift/UVOT UV grism spectrum results
- GRB 260924A: AbAO optical observations
- GRB 260924A: Upper limits from a neutrino search with IceCube
- GRB 260924A: Near-infrared detection with MDM/MIRAGE
- GRB 260924A: COLIBRÍ optical observations
- GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
- Konus-Wind detection of GRB 260924A
- GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
- GRB 260924A: Optical follow-up observations with Kinder
- GRB 260924A: Ondrejov D50 optical afterglow detection
- GRB 260924A: SVOM/GRM observation
- GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
- GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
- GRB 260924A: Swift/UVOT Detection
- GRB 260924A: GROWTH-India Telescope optical observations
- GRB 260924A: Swift-BAT refined analysis
- GRB 260924A: NuSTAR detection of prompt emission
- GRB 260924A: Swift/UVOT Upper Limits
- GRB 260924A: Swift-XRT refined Analysis
- GRB 260924A: Fermi GRB Observation
- GRB 260924A: Fermi-LAT detection of a bright burst
- GRB 260924A: AstroSat CZTI detection
- GRB 260924A: NOT optical counterpart confirmation
- GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
- GRB 260924A: Enhanced Swift-XRT position
- GRB 260924A: Swift detection of a burst