TITLE:   GCN CIRCULAR
NUMBER:  44334
SUBJECT: EP260416a: GMG Optical Observation
DATE:    26/04/18 01:02:53 GMT
FROM:    Rui-Zhi Li at Yunnan Observatories, CAS <liruizhi@ynao.ac.cn>

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

We observed the field of EP260416a (Hu et al., GCN 44307, T0 at 2026-04-16T05:29:32) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2026-04-17T15:58:05, about 34.48 hours after the trigger.

The optical counterpart of EP260416a (Ducoin et al., GCN 44310; Li et al., GCN 44315; Hua et al., GCN 44318; Lee et al., GCN 44319; Zheng et al., GCN 44321; Martin-Carrillo et al., GCN 44328) was well detected.

The preliminary analysis results are shown as follows:
+---------------+------------+----------+--------------+----------------+
|  Tmid-T0 [h]  |  Exp. [s]  |  Filter  |     Mag      |  5-sigma U.L.  |
+===============+============+==========+==============+================+
|    34.50      |    180     |    r     | 20.91 ± 0.07 |      22.3      |
+---------------+------------+----------+--------------+----------------+ 
The given magnitudes are derived based on calibration against Pan-STARRS1 field stars, and are not corrected for the expected Galactic foreground extinction, corresponding to a reddening of E(B-V) = 0.008 mag in the direction of the optical counterpart (Schlafly & Finkbeiner 2011).