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.