GCN Circular 32360
Subject
GRB 220708B: T193-OHP optical upper limit
Date
2022-07-10T20:54:34Z (2 years ago)
From
Damien Turpin at NAOC (CAS) <dturpin-astro@hotmail.com>
D. Turpin (CEA), C. Adami (LAM), B. Schneider,
E. Le Floc�h (CEA), S. Basa (LAM) report on behalf of
a larger collaboration:
We observed the field of GRB 220708B (Tohuvavohu et al. GCN 32345,
Kobayashi et al. GCN 32356, Frederiks et al. GCN 32358) using the T193cm
telescope at Observatoire de Haute-Provence (France) equipped with the
MISTRAL spectro-imager. Six exposures (6x600s) were obtained in the r band
using the bleu MISTRAL set-up from 2022 08 Jul 20:55:39 UT to 2022 08 Jul
22:14:27 UT (mid time ~19.5h after trigger). In the combined frame, we do not
detect any source within the 4 arcsec error circle of the XRT position
(Osborne et al. GCN 32350) down to the following 3-sigma limit:
r > 22.3 mag (AB)
The photometric calibration was performed using nearby stars
from the PanSTARRS catalog. The magnitude is not corrected
for Galactic extinction and it is consistent with the non-detections
reported by Jiang et al. (GCN 32355).
We express our deepest thanks to the Observatoire de Haute-Provence for its
support, in particular to St�phane Favard and J�r�me Schmitt.