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GCN Circular 39476

Subject

EP250223a: GMG Optical Observation

Date

2025-02-26T04:26:24Z (2 months ago)

From

Boting Wang at Yunnan Observatories, CAS <wangbaiting@ynao.ac.cn>

Via

Web form

B.-T. Wang, R.-Z. Li, F.-F. Song, J. Mao, D.-Q. Wang, and J.-M. Bai (YNAO, CAS) report:

We observed the field of EP250223a (Lian et al., GCN 39429

, T0 at 2025-02-23T15:04:35.749) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2025-02-25T12:45:36.92, about 45.68 hours after the trigger. The optical counterpart of EP250223a (Hauptmann et al., GCN ; Wu et al., GCN ; Pérez-Fournon et al., GCN ; Izzo et al., GCN ; Xin et al., GCN ; Guo et al., GCN ; An et al., GCN ; Ducoin et al., GCN ; O’Neill et al., GCN ; Aryan et al., GCN ; Saikia et al., GCN ), with a redshift of 2.756 (Levan et al., GCN ), was detected within the error box of EP/FXT (Lian et al., GCN ).

The preliminary analysis results are shown as follows:

tmid-t0 (hours)	Filter	Exposure (s)	Magnitude (AB)	5-sigma U.L.
45.85	sdssr	1200	20.82 +/- 0.08	21.9

The given magnitudes are derived based on calibration against Pan-STARRS1 field stars and are not corrected for the expected Galactic foreground extinction.

We warmly thank the staff at the Lijiang Observatory for their efforts in conducting the observation.