TITLE:   GCN CIRCULAR
NUMBER:  33800
SUBJECT: GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
DATE:    23/05/14 23:03:22 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

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

We observed the field of Fermi LAT localization (Maheso et al., GCN 33780) of short bright GRB 230512A (Fermi GBM team, GCN 33778; AstroSat, GCN 33779 and GRBAlpha, GCN 33795)
using the NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.

No optical source is detected in our stacked images at the XRT source 5 position. Preliminary photometric results are as follows:

T_mid-T0(day)   Filter   Upper_Limit(3-sigma)
    0.537              r          20.7
    1.543              r          21.8
    1.563              z          20.0

calibrated with the nearby PS1 stars and not corrected for Galactic extinction. The NEXT's first epoch image doesn't reveal the Kitab candidate (Belkin et al., GCN 33796), although it is deeper.

Some other XRT sources are also covered, and so far no credible optical afterglow candidate can be claimed.