GCN Circular 37862
Subject
GRB 241025A: TRT optical afterglow observation
Event
Date
2024-10-25T03:35:44Z (9 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
S.Q. Jiang (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), Z.P. Zhu, S.Y. Fu, J. An, X. Liu, Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang, D. Xu (NAOC) report on behalf of a large collaboration:
We observed the field of GRB 241025A detected by Swift (Ambrosi et al., GCN 37859), EP (EP241025a, ID: 01709111485), Fermi (Fermi GBM team, GCN 37860), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Fresno, California, US. Observations started at 02:24:10.976 UTC on 2024-10-25, i.e., 47.34 mins after the Swift trigger, and a series of 200 s frames were obtained in R-band.
The optical afterglow by Swift/UVOT (Ambrosi et al., GCN 37859) is clearly detected in our individual as well as stacked images. Its brightness is varying and has R = 19.68 +/- 0.12 mag in the first image at a median time 0.817 hr after the Swift trigger, calibrated with PanSTARRS and not corrected for Galactic extinction.