TITLE: GCN CIRCULAR NUMBER: 33340 SUBJECT: GRB 230216A: SVOM/C-GFT optical upper limit DATE: 23/02/18 04:38:35 GMT FROM: Chao Wu at NAOC Zhe Kang (CHO), Liping Xin (NAOC), Chao Wu (NAOC), Xuhui Han (NAOC), Xiaomeng Lu (NAOC), Damien Turpin(CEA), Zhenwei Li (CHO)���Pinpin Zhang (NAOC)���Ruosong Zhang (NAOC)���Yulei Qiu (NAOC)���You Lv (CHO)���Jing Wang(GXU), Cordier Bertrand (CEA) and Jianyan Wei (NAOC) on behalf of SVOM GRB team We observed the burst GRB230216A (Klingler et al. GCN Circ. 33328) on 14:50:01 UT, Feb. 16th, 2023, about 87 seconds after the Swift 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 1.5 deg X 1.5 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope. A series of g and r band images were obtained. The exposure time was 10-30 seconds for each frame. The bright star USNO-B1 0819-0175793 is located within the XRT enhanced error box (Osborne et al., GCN 33331) which has been reported (Gendre et al.,GCN 33329; Mohammad Odeh GCN 33330). No optical afterglow was detected with an image subtraction by the first r band image with an image obtained 43 minutes after. A limit magnitude of 18.5 mag is derived for r-band single frame (in STM) after calibration with nearby UCAC 4 catalogs. More detailed analysis is continuing. We thank the observation assistant Bowen Li at Jilin observatory for their excellent support. This message may be cited.