TITLE:   GCN CIRCULAR
NUMBER:  38972
SUBJECT: EP250108a / AT2025kg: GMG Optical Observations
DATE:    25/01/18 04:40:23 GMT
FROM:    Fei-Fan Song at Yunnan Observatories <songfeifan@ynao.ac.cn>

F.-F. Song, R.-Z. Li, B.-T. Wang, J. Mao, K.-X. Lu and J.-M. Bai (YNAO) report:

We observed the field of EP 250108a (Li et al., GCN 38861, T0 at 2025-01-08T12:30:28.34 UTC) using the GMG-2.4m telescope at the Lijiang Observatory. The observations were made three times, starting at 2025-01-15T14:26:43, 2025-01-16T12:33:50 and 2025-01-16T12:38:36, respectively. The optical counterpart of EP 250108a (Eyles-Ferris, GCN 38878; Zhu et al., GCN 38885; Malesani et al., GCN 38902; Kumar et al., GCN 38907; Zhu et al, GCN 38908; L. Izzo, GCN 38912; Zou et al., GCN 38914; Moskvitin et al., GCN 38925) was detected.

The preliminary analysis results are shown as follows:
+---------------+----------+--------------+--------------+
|  Tmid-T0 [h]  |  Filter  |     Mag      |  5-sigma UL  |
+===============+==========+==============+==============+
|     170.10    |     r    | 20.75 ± 0.16 |     21.1     |
+---------------+----------+--------------+--------------+
|     192.09    |     g    | 20.78 ± 0.09 |     21.7     |
+---------------+----------+----------+------------------+
|     192.17    |     r    | 20.28 ± 0.07 |     21.6     |
+---------------+----------+--------------+--------------+

The given magnitudes are derived based on calibrating against Pan-STARRS1 field stars. We acknowledge the staff at the Lijiang Observatory for conducting the observation.