TITLE: GCN CIRCULAR NUMBER: 41618 SUBJECT: GRB 250831A (SVOM trigger sb25083102) is likely an outburst from star G 272-61 DATE: 25/08/31 13:56:49 GMT FROM: SVOM_group svomgroup@bao.ac.cn
W.J. Xie, L. Lan, L.P. Xin (NAOC), Francesco Magnani (CPPM), D. B. Malesani (DAWN/NBI and Radboud) report on behalf of the SVOM mission team:
At 2025-08-31T09:29:33 UTC SVOM issued an alert with burst-id sb25083102, which was previously referred to as GRB 250831A (Xie et al., GCN 41614).
We found that there are several X-ray sources within the error box of ECLAIRs, including the high proper motion star G 272-61 (distance: 2.7 pc). This source was also noticed by Wu et al., (GCN 41615) in VT and Magnani et al. (GCN 41616) in COLIBRÍ (FM-GFT) images. Considering the proper motion of the source and the distance from the MXT localization (Xie et al., GCN 41614) and the XRT position (Evans et al., GCN 41617), we proposed that this SVOM trigger originated from an X-ray outburst of this star, and not an extragalactic GRB.
We apologize for any inconvenience this may have caused.
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE.
The Burst Advocate (BA) on shift for this alert is: Wenjin XIE (xiewj@bao.ac.cn) Please contact the BA by email if you require additional information.
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