TITLE:   GCN CIRCULAR
NUMBER:  44232
SUBJECT: EP-WXT01709259586: Xinglong optical upper limit
DATE:    26/04/07 15:12:09 GMT
FROM:    Xinglong Observatory at National Astronomical Observatories (NAOC), Chinese Academy of Sciences (CAS) <xinglong@nao.cas.cn>

Min-He (NAOC),  Junjie-Jin (NAOC), Haiyang-Mu (NAOC), Feng-Xiao (NAOC), Pengliang-Du (NAOC), Zhou-Fan (NAOC), Hong-Wu (NAOC) report on behalf of a large collaboration:

Following the detection of EP-WXT01709258519, we observed the field of EP-WXT01709259586 (Wu et al. GCN 44213) using the 2.16-m telescope at Xinglong Observatory, NAOC. We obtained 3x300s clear-band frames with a median time of 2026-04-07T12:58:22, 3 days after the EP trigger.

No uncatalogued optical transient is detected in the stacked images within the 3 arcmin EP/WXT error circle (WXT01709259586), down to 3-sigma limiting magnitudes of 22.31 mag for 2.16-m, calibrated with Pan-STARRS sources in the field. Also there is no apparent brightening for the catalogued sources within the error circle.