GCN Circular 39901

Subject

GRB 250322A: GRANDMA/TNOT optical upper limits

Event

GRB 250322A

Date

2025-03-28T09:01:10Z (a year ago)

From

duverne@apc.in2p3.fr

Via

Web form

E. Elhosseiny (NRIAG), N. Kochiashvili (AbAO), O. Pyshna (Caltech), Haichang Zhu (THU), A. Iskandar(XAO), Xiaofeng Wang (THU), Letian Wang (XAO) C. Andrade (UMN), S. Antier (OCA/IJCLAB), M. Coughlin (UMN), P-A. Duverne (APC), N. Guessoum (AUS), P. Hello (IJCLAB), S. Karpov (FZU), T. Pradier (Unistra/IPHC), D. Turpin (CEA-Saclay/Irfu) on behalf of the GRANDMA and Kilonova-Catcher collaborations:

The field of GRB 250322A (Gupta et al., GCN 39835

, Goad et al. GCN , Perri et al. GCN , Sadaula et al. GCN ) has been imaged with the 80~cm Tsinghua-Nanshan Optical Telescope (TNOT) located at Nanshan Station of Xinjiang Astronomy observatory 1.1h post trigger with the r' filter for a total exposure of 100s.

We do not detect any new source at the enhanced Swift-XRT position (Goad et al. GCN 39841

) down to r<21.2 AB mag (5-sigma) calibrated with nearby Pan-STARRS stars and without Galactic extinction correction. All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2025 Acta Polytechnica, 65(1), 50-64).

We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023).

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/).