GCN Circular 42041
Subject
GRB 251001B: TRT optical afterglow detection and potential host galaxy
Event
Date
2025-10-01T15:17:04Z (a day ago)
From
sqjiang at NAOC <sqjiang@bao.ac.cn>
Via
Web form
J. An, X. Liu (NAOC), K. Noysena, K. Chanchaiworawit, S. Tinyanont (NARIT), S.Q. Jiang, L.B. He, Z.P. Zhu, D. Xu (NAOC), S.Y. Fu (HUST) report on behalf of a large collaboration:
We observed the field of GRB 251001B detected by Swift/BAT (Beardmore et al., GCN 42039), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at New South Wales, Australia (SBO). A series of images were obtained in the R band.
A varying optical transient (OT) is detected within the Swift/XRT error circle at coordinates
R.A. (J2000) = 2:50:36.33
Dec.(J2000) = -23:01:11.96
with an uncertainty of ~ 0.6 arcsec. It has R ~ 18.9 mag at 21.1 min after the Swift/BAT trigger. We thus think the OT is the optical afterglow of the burst.
We also note that there is a galaxy at the OT position from Legacy Survey DR10 with g ~ 25.16, r ~ 24.93, i ~25.06, z ~24.79, and a phot_z ~ 1.14 +/- 0.53, which is presumably the host galaxy of the burst.