GCN Circular 36206
Subject
EP240420a: GWAC-F50A optical upper limit
Date
2024-04-21T07:47:22Z (13 days ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
legacy email
L. P. Xin(NAOC), Y. G. Yang(HNU), C. WU(NAOC), Y. L. Qiu(NAOC), J. Wang(GXU/NAOC),
H. L. Li(NAOC), C. Wu(NAOC), E. W. Liang(GXU), X. H. Han(NAOC), X. M. Lu(NAOC),
R. S. Zhang(NAOC), Y. Xu(NAOC), Y.J . Xiao(NAOC), P. P. Zhang(NAOC), L. Lan(NAOC),
J. Y. Wei(NAOC) on behalf of the SVOM/GWAC team:
We began to observe X-ray transient EP240420a (Zhang et all., GCN 36194)
detected by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission,
with GWAC-F50A telescope at Xinglong station, China, at 13:58:11 (UT), 20. April. 2024,
about 1.9 hours after the burst.
The weather was not good.
After stacking 100*100s seconds, the candidate reported (An et al., GCN 23602)or
any other new sources were not detected within the errorbox of EP-FXT (Han et al., GCN 23603)
in our stacked image down to a limit magnitude of 19.5 mag
in R band comparing to several nearby USNO B1.0 stars.
We acknowledge the excellent support from observation assistant Yangtong ZhengandWenlongDong.