GCN Circular 37413
Subject
GRB 240905E: SVOM/C-GFT optical upper limit
Date
2024-09-06T13:36:12Z (3 months ago)
From
Chao Wu at NAOC <cwu@nao.cas.cn>
Via
Web form
SVOM/C-GFT team: Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC)
SVOM JSWG: Jian-Yan Wei (NAOC, China), Bertrand Cordier (CEA, F), Shuang-Nan Zhang (IHEP, CN), Stephane Basa (LAM, F), Jean-Luc Attéia (IRAP, F), Arnaud Claret (CEA, F), Zi-Gao Dai (USTC, CN), Frederic Daigne (IAP, F), Jin-Song Deng (NAOC, CN), Andrea Goldwurm (APC, F), Diego Götz (CEA, F), Xu-Hui Han (NAOC, CN), Cyril Lachaud (APC, F), En-Wei Liang (GXU, CN), Yu-Lei Qiu (NAOC, CN), Susanna Vergani (Obs.Paris, F), Jing Wang (NAOC, CN), Chao Wu(NAOC, CN), Li-Ping Xin (NAOC,CN), Bing Zhang (UNLV, CN)
We observed the field of the GRB 240905E detected by Swift/BAT (Dichiara et al., GCN 37397) and SVOM/GRM (Zhang et al., GCN 37404) starting at 18:49:20 UT, 5 Sep. 2024, ~ 0.36 hr after the burst trigger with C-GFT (Chinese Ground Follow-up Telescope in SVOM mission) in System Test Mode (STM). C-GFT is located at Jilin (long.=126.33 deg, lat.= 43.8243778 deg), Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope.
A series of g, r, and i band images were obtained. We obtained stacked images of g: 108x10s, r: 102x 10s and i: 102x10s. No any optical counterpart was detected within the X-ray afterglow error circles (Dichiara et al., GCN 37397) down to the limiting magnitude (3 sigma) of mag_g=21.5, mag_r=21.7, and mag_i=21.3 . It is consistent with the results reported by Lipunov et al.(GCN 37398), Jiang et al. (GCN 37399), Moskvitin et al. (GCN 37401), Shilling et al. (GCN 37402), Strausbaugh et al. (GCN 37403), Brivio et al. (GCN 37408), Fu et al. (GCN 37409) and Adami et al. (GCN 37412).
The photometry was calibrated with nearby Pan-STARRS 1 catalog.
We thank the observation assistants Bowen Li and Guangsheng Zhang at Jilin observatory for their excellent support.