TITLE:   GCN CIRCULAR
NUMBER:  38929
SUBJECT: GRB 250114A: TRT optical observations
DATE:    25/01/14 08:35:39 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

J. An (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), X. Liu, Z.P. Zhu, S.Y. Fu, S.Q. Jiang, D. Xu (NAOC) report on behalf of a large collaboration:

We observed the field of GRB 250114A detected by Swift (Klingler et al., GCN 38927), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Cerro Tololo, Chile. Observations started at 07:46:08.50 UTC on 2025-01-14, i.e., 13 mins after the Swift trigger, and a series of R-band frames were obtained.

The optical afterglow by Swift/UVOT (Klingler et al., GCN 38927) is clearly detected in the stacked images. Its brightness is decaying and has r ~ 20.2 mag at a median time 14.5 mins after the Swift trigger, calibrated with PanSTARRS and not corrected for Galactic extinction.