GCN Circular 39926
Subject
GRB 250329B: GWAC-F50A optical upper limit
Date
2025-03-29T13:31:32Z (6 days ago)
Edited On
2025-03-31T02:04:07Z (5 days ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
Web form
L. P. Xin(NAOC), Y. G. Yang(HNU), X. H. Han, C. WU, Y. L. Qiu, J. Wang, H. L. Li, X .M. Lu, R. S. Zhang, Y. Xu, L. Huang, H. B. Cai, Y. J. Xiao, P. P. Zhang, L. Lan, W. J. Xie, Z. H. Yao, J. Y. Wei(NAOC), X. G. Wang, E. W. Liang(GXU) report on behalf of the SVOM/F50A team:
We began to observe GRB 250329B (Xie et al., GCN 39925) with 50cm telescope (GWAC-F50A) at Xinglong station, China, at 2025-03-29T12:27:17.58 (UT), about 7.0 min after the burst.
With the first observations with exposure time of 4*100 sec, no any uncatalogued source was detected in our stacked image down to a 3 sigma limit magnitude of 18.5 mag in R band, at the mid time of 10.3 min after the burst, comparing to several nearby USNO B1.0 stars.
Further observations are ongoing.
We acknowledge the excellent support from observation assistant Yatong Zheng and Wenlong Dong.