TITLE:   GCN CIRCULAR
NUMBER:  46247
SUBJECT: GRB 261113A: K-band infrared counterpart candidate by the SYSU 80cm infrared telescope
DATE:    26/11/13 15:48:25 GMT
FROM:    linp@mail2.sysu.edu.cn

Pu Lin, Jing-Kai Sun, Zhong-Nan Dong, Jin-Ji Li, Yun Shi, Rui-Chen Gao, Jia-Qi Lin, Hao-Nan Yang, Hao-Ran Zhang, Jian-Hong Cao, Shu-Quan Bai, Si-Rui Huang, Lu-Yao Wen, Zhi-Xiang Tan, P. H. Thomas Tam, Rong-Feng Shen, and Bin Ma (Sun Yat-sen University) report on behalf of the SYSU 80cm infrared telescope team:

We observed the field of GRB 261113A, detected by SVOM/ECLAIRs (A. Saccardi et al., GCN 46244), using the Sun Yat-sen University (SYSU) 80 cm infrared telescope in the K band. Our observations were carried out on 2026-11-13 from 14:37:32 to 15:09:43 UT (from ~6.5 to ~38.7 minutes after the SVOM/ECLAIRs trigger), using stacked images in the K band (73 x 20 s, 1460 s total exposure).

In the stacked image, we detect a point-like near-infrared source at the following coordinates (J2000):
RA = 23:05:16.94 (346.320585)
Dec = +05:10:19.27 (+5.172020)
The source is located approximately 65 arcsec from the reported SVOM/ECLAIRs position (A. Saccardi et al., GCN 46244), slightly outside the quoted 47 arcsec error radius, and we measure a magnitude of:
K = 16.49 +/- 0.083 mag (Vega).
Further observations are ongoing.

The photometry was calibrated against nearby stars from the 2MASS catalog and is reported in the Vega system, without correction for Galactic extinction.

The SYSU 80 cm infrared telescope is operated and managed by the Department of Astronomy, Sun Yat-sen University.