TITLE: GCN CIRCULAR NUMBER: 42833 SUBJECT: EP251124a: Xinglong GWAC-F60A optical observation DATE: 25/11/25 09:48:40 GMT FROM: Yinuo Ma mayn@bao.ac.cn
Y. N. Ma, L. P. Xin, Y. L. Qiu, C. Wu, J. Wang, X. H. Han, P. P. Zhang, H. L. Li, Z. H. Yao, J. Y. Wei (NAOC) report on behalf of SVOM follow-up team:
We observed the field of EP251124a triggered by EP/WXT (Zhou et al., GCN 42816; GCN 42832) using the GWAC-F60A telescope located at Xinglong observatory, China. We obtained a series of frames in R-band, starting at 2025-11-24T11:22:30 UTC, about 12.42 minutes after the trigger.
No uncataloged sources were detected in our single or stacked images within the error box provided by EP/FXT (Zhou et al., GCN 42816) and Swift/XRT (Evans et al., GCN 42827), the three sigma limit is:
mid-time | exposure time | band | upper limit ----------- -|-----------------|-------|------------- 19.5 minutes | 10*50 sec | R | 19.5 mag
None of the known sources showed significant brightness variations within EP/FXT and Swift/XRT errorbox compared with USNO-B1.0 catalog. Our results are consistent with GIT (Mohan et al., GCN 42817), Kinder (Wang et al., GCN 42824), MASTER (Lipunov et al., GCN 42828), and NOT (van Hoof et al., GCN 42829).
Our photometry was not corrected for Galactic extinction.
We thank the staff at Xinglong observatory for their excellent support.
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