GCN Circular 43047
Subject
GRB 251208D: LCO analysis of the XRT sources
Event
Date
2025-12-09T12:07:14Z (a day ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
D. B. Malesani (DAWN/NBI and Radboud), D. Turpin, A. Saccardi (CEA/Irfu), Z.-Y. Lin, F. Cangemi (APC), report on behalf of the SVOM mission team:
Following the report of two X-ray sources detected by Swift/XRT (Evans et al., GCN 43043), we inspected again our images taken with LCO (Turpin et al., GCN 43037) of the field of the SVOM GRB 251208A (Lin et al., GCN 43032).
* XRT source #1 matches the high proper-motion star TYC 5226-156-1 (distance ~500 pc). We measure a magnitude of r = 11.34 +- 0.02, consistent with the APASS archival value r = 11.34 +- 0.06.
* XRT source #2 is consistent with SDSS J223038.66-003108.3, a known QSO at z = 1.32 with magnitude r = 20.34 (from SDSS) and r = 20.65 (from Pan-STARRS), possibly indicating some long-term variability. We measure r = 20.73 +- 0.12, indicating that the object is not in a particularly active state.
Our observations suggest that neither sources are likely related to the high-energy emission observed by SVOM.
This project is funded by the SVOM collaboration.