TITLE:   GCN CIRCULAR
NUMBER:  33534
SUBJECT: GRB 230328B: Nanshan/NEXT optical upper limit
DATE:    23/03/29 03:45:19 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

T.H. Lu, S.Q. Jiang, S.Y. Fu, X. Liu (NAOC), Z.P. Zhu (NAOC, HUST), D. 
Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 230328B detected by Swift (Gropp et al., 
GCN 33527),using the NEXT-0.6m optical telescope located at Nanshan, 
Xinjiang, China. Observations started at 16:39:57 UT on 2023-03-28, 
i.e., 1.75 hr after the Swift/BAT trigger.

The previously reported optical afterglow (e.g., Pankov et al., GCN 
33528; Belkin et al., GCN 33530) is marginally detected in our stacked 
image. Preliminary photometry of the afterglow has r ~ 19.1 mag, 
calibrated by nearby PanSTARRS stars.