TITLE:   GCN CIRCULAR
NUMBER:  46249
SUBJECT: GRB 261113A: GMG Optical Observation
DATE:    26/11/13 16:36:35 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 GRB 261113A (Saccardi et al., GCN 46244, T0 at 2026-11-13T14:31:02) using the GMG-2.4m telescope at the Lijiang Observatory. 
The observation began at 2026-11-13T15:23:45, about 0.88 hours after the trigger.

The optical counterpart (Lin et al., GCN 46247; Lei et al., GCN 46248) was well detected in our r-band image.

The preliminary analysis results are shown as follows:

   Start time [UTC]       Exposure [s]    Tmid-T0 [h]    Filter    AB Magnitude    5-sigma U.L.
-----------------------  --------------  -------------  --------  --------------  --------------
2026-11-13 15:23:45.073       300            0.92          r       19.39 ± 0.02        22.3 

The given magnitudes are derived based on calibration against Pan-STARRS field stars, and are not corrected for the expected Galactic foreground extinction, corresponding to a reddening of E(B-V) = 0.052 mag in the direction of the optical counterpart (Schlafly & Finkbeiner 2011).