GCN Circular 43778

Wenjin TAN (IHEP), Chao WU (NAOC), Wenjin XIE (NAOC), Hatsune GOTO (Kanazawa Univ.), Pierre MAGGI (ObAS) , report on behalf of the SVOM mission team:

At 2026-02-18T05:15:18 UTC (T0), SVOM/ECLAIRs triggered and located an X-ray transient (SVOM burst-id sb26021801).

The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.

The burst was only detected by the Image Trigger (IMT), which produced a sequence of 1 alert. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 8.29 in the 5-20 keV energy band over a time window of 1310.72 seconds starting at 2026-02-18T04:53:28.
The localization of the best alert is R.A., Dec. 194.8408, 27.9434 degrees:
R.A. (J2000) = 12h59m21.80s
Dec. (J2000) = 27d56m36.21s
 with a 90% confidence level (C.L.) radius of 9.50 arcmin (including systematic error of 2 arcmin added in quadrature).

The Coma Cluster (ACO 1656) and its Brightest Central Galaxy NGC 4874 are within the trigger error circle and may be the source triggering the ECLAIRs telescope.

Due to the detection significance being below the slew threshold, no immediate slew was performed on this burst.
No X-ray observation could be performed by SVOM/MXT for the time being. No optical observation could be performed by SVOM/VT for the time being.

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 Wenjun Tan: tanwj@ihep.ac.cn.
Please contact the BA by email if you require additional information.