GCN Circular 45323
Subject
GRB260808B: OHP/T193 optical observations
Event
Date
2026-08-09T03:41:48Z (2 days ago)
Edited On
2026-08-10T13:20:24Z (9 hours ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
C. Adami (LAM/Pytheas/AMU), E. Le Floc'h (CEA/Irfu), B. Schneider (LAM), A. Saccardi (CEA/Irfu), S. Basa (LAM/OHP/Pytheas/AMU) report on behalf of a larger collaboration:
We observed the field of GRB 260808B (Bouchet et al., GCN45316; see also Wang et al., GCN45322) using the T193cm telescope at Observatoire de Haute-Provence (France) with the MISTRAL spectro-imager. We obtained 7x10 + 1x5 minutes of exposure in the i-band and 6x20minutes in the Y-band under a 2.3arcsec seeing, starting at 20260808_223518UT (~8.3 hr after the Bouchet et al. trigger) and ending at 20260809_021419UT (~11.9 hr after the Bouchet et al. trigger).
In the preliminary stacked images, we detect in i’ band the afterglow at the position of Turpin et al. (GCN 45318) and Li et al. (GCN 45320) at a preliminar magnitude of:
i = 22.63 +/- 0.13 mag
We do not detect the source in our Y-band image. This image has a preliminar estimated limiting magnitude of Y=21.8 (3sigma).
The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the STDWeb/STDPipe tools (Karpov 2025), is in the AB system, and is not corrected for Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Stephane Favard.