A. Iskandar (XAO), F. Wang (THU/BJP), J. Zhu (BJP), L. Wang, X. Zeng, C. Andrade (UMN), A. de Ugarte Postigo (CNRS/OCA), D. Akl (AUS), E. Broens (KNC), S. Antier (OCA-Artemis), I. Tosta e Melo (UniCT-DFA), P. Hello (IJCLAB), D. Turpin (CEA-Saclay/Irfu), T. Pradier (Unistra/IPHC), M. Coughlin (UMN), S. Karpov (FZU), J. Peloton (IJCLab) report on behalf of the GRANDMA collaboration:
We observed the field of GRB 231115A (Fermi GBM team, GCN 35035) covering the complete INTEGRAL error box (D’Avanzo et al. GCN 35036;Mereghetti et al. GCN 35037) within the GRANDMA collaboration. Imaging with the 0.4m SNOVA telescope did not find any candidate in r-band around 2023-11-15 17:37:53 (e.g 2h after the trigger time) down to an upper limit of 18.9 (5-sigma threshold) or 19.3 (3-sigma threshold) using PS1 catalog as photometric comparison. We also looked carefully at the location of AT 2023xvj (Kumar et al. GCN 35041).
The amateur contribution to GRANDMA, Kilonova Catcher (KNC), made no detection with a 30x180s image using a clear filter on 2023-11-15T20:00 UTC (TGRB + 3.28h). We determine a detection limit of 20 mag in r-band, using PS1 for calibration and color term correction. At 2023-11-15T18:53:25.219, we obtained R>18 from 5x180s exposure. The upper limit is given at 5-sigma averaged over all the images.
These upper limits are consistent with previous reports by MASTER (Lipunov et al. GCN 35046).
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).