[vsnet-grb-info 27295] GRB 210205A： GWAC-F60A optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29398
SUBJECT: GRB 210205A： GWAC-F60A optical upper limit 
DATE:    21/02/05 11:50:51 GMT
FROM:    Liping Xin at NAOC, SVOM  <xlp at nao.cas.cn>

L. P. Xin(NAOC),  J. Wang(GXU), C. Gao(GXU), X. H. Han(NAOC), J. Y. Wei(NAOC), 
G. W. LI(NAOC),  L. H. Li(NAOC), C. Wu(NAOC),  X. G. Wang(GXU), 
E. W. Liang (GXU), R. S. Zhang(NAOC), Y. L. Qiu(NAOC), 
and J. S. Deng(NAOC) report: 

We began to observe GRB 210205A (Dichiaraet al., GCN 29397)
with Xinglong GWAC-F60A telescope, China, 
at 11:13:26 (UT), 5th. Feb. 2021, about 129 sec after the burst.

A series of  R, I, and B band images were obtained.
Preliminary analysis shows that no any new optical source
are found in single images within the XRT errorbox (Dichiaraet al., GCN 29397). 

The 3 sigma upper limit is about 17.3 mag in R band 
at the mean time of 134 sec after the burst,
calibrated to the USNO B1.0 catalog.