TITLE:   GCN CIRCULAR
NUMBER:  39822
SUBJECT: EP250321a: Xinglong 216 decaying optical observations
DATE:    25/03/21 19:24:45 GMT
FROM:    Xinglong Observatory at National Astronomical Observatories (NAOC), Chinese Academy of Sciences (CAS) <xinglong@nao.cas.cn>

Junjie-Jin (NAOC), Haiyang-Mu (NAOC), Jinlei-Zhang (NAOC), Pengliang-Du (NAOC), Feng-Xiao(NAOC),Zhou-Fan (NAOC), Hong-Wu (NAOC) 
We performed optical observations of the field of a fast X-Ray transient EP250321a (Hu et al., GCN 39800) in the Free filter using 2.16-m telescope located at Xinglong, Hebei, China. In the band a 600 s exposures were taken , with a median observation time of 2025-03-02T20:32:28. 
No uncatalogued optical transient is detected in the stacked images within the 3 arcmin EP/WXT error circle (Li et al., GCN 36405), down to 3-sigma limiting magnitudes of g ~ 20.5, calibrated with Pan-STARRS sources in the field. Also there is no apparent brightening for the catalogued sources within the error circle.