TITLE: GCN CIRCULAR NUMBER: 36315 SUBJECT: EP240426a: GMG optical upper limit DATE: 24/04/26 14:10:11 GMT FROM: wangbaiting@ynao.ac.cn B.-T. Wang, R.-Z. Li, J. Mao, L.-Y. Zhu, Y.-Z. Cai, J.-M. Bai (YNAO) report: We observed the field of EP-FXT detection of the candidate conterpart EP 2406026a (Sun et al. GCN 36313) by the GMG-2.4m telescope at the Lijiang station in Yunnan Observatories. The observation began at 2024-04-26T12:37:20. No optical counterpart was detected within the EP-FXT error circle. The very preliminary upper limit can be given i>18.7.