TITLE:   GCN CIRCULAR
NUMBER:  43425
SUBJECT:  EP260116a: Xinglong optical upper limit
DATE:    26/01/16 16:49:09 GMT
FROM:    Xinglong Observatory at National Astronomical Observatories (NAOC), Chinese Academy of Sciences (CAS) <xinglong@nao.cas.cn>

Junjie-Jin (NAOC), Haiyang-Mu (NAOC), Sen-Liu (NAOC), Pengliang-Du (NAOC),
Zhou-Fan (NAOC), Hong-Wu (NAOC) report:
Following the detection of EP260116a by EP-WXT (GCN Circular 43424), we observed the field of EP260116a using the 2.16-m
telescope at Xinglong Observatory, NAOC. We obtained 3x300s clear-band frames with a
median time of 2026-01-16T15:26:52 hr after the EP trigger.
No uncatalogued optical transient is detected in the stacked images within the 3 arcmin
EP/WXT error circle (GCN Circular 43424), down to 5-sigma limiting magnitudes of N ~
20.8, calibrated with Pan-STARRS sources in the field. Also there is no apparent brightening
for the catalogued sources within the error circle.