TITLE:   GCN CIRCULAR
NUMBER:  34404
SUBJECT: GRB 230812B: GMG - GRANDMA observations
DATE:    23/08/13 14:40:05 GMT
FROM:    Jirong Mao at Yunnan Obs <jirongmao@mail.ynao.ac.cn>

J. Mao, K.-X. Lu, J.-M. Bai (YNAO), S. Karpov (FZU), M. C. Coughlin (UMN), A. Ugarte Postigo, S. Antier (OCA), O. Pyhsna (Univ. KieV), Z. Vidadi (Shao) on behalf of the Yunnan observatories team and the GRANDMA team:

We observed the field of GRB 230812B (Lesage et al. GCN 34387; Scotton et al. GCN 34392; Page GCN 34394; Zheng & Filippenko GCN 34395; Lipunov et al. GCN 34396; Salgundi et al. GCN 34397; Ackley et al. GCN 34398; Xiong et al. GCN 34401; Casentini et al. 34002; Frederiks et al. 34404) by the GMG telescope in Yunnan observatories. The observation began from UT 13:34:22 August 13, 2023, about 18.5 hours from the trigger. We clearly observed the optical afterglow of R~19.9+/-0.1. The further observation is ongoing.