General information
GRB 260802A was detected by SVOM/ECLAIRs at 2026-08-02T09:23:10 UTC as a short, soft burst lasting about 0.2 s, with a best reported image SNR of 8.09 in 5-20 keV. The event is repeatedly noted as possibly associated with the magnetar/SGR candidate EP J223759.5+531421.
Wavelength coverage
- Gamma-ray / hard X-ray: SVOM/ECLAIRs triggered and localized the burst at R.A. 339.4431 deg, Dec. 53.2195 deg, with a 90% confidence radius of 9.72 arcmin.
- X-ray: SVOM/MXT began observations 151 s after trigger and reported a possible low-SNR uncatalogued X-ray source at R.A. 339.439 deg, Dec. 53.234 deg with a 90% confidence radius of 161 arcsec.
- Optical: COLIBRI z-band imaging found no new source, with limits z > 22.6 at the ECLAIRs position and z > 23.1 at the XMM magnetar localization; LCO found r > 20.96 AB; SVOM/VT found no counterpart with limits up to VT_B > 23.0 and VT_R > 23.0 AB.
Bands with no observations mentioned: radio, infrared, ultraviolet, neutrino, gravitational-wave.
Lightcurve and spectrum
- SVOM/ECLAIRs reported a single peak structure lasting about 0.2 s.
- The burst was detected by the Count-Rate Trigger only, with three alerts and best SNR 8.09 in the 5-20 keV energy band.
- Optical observations reported non-detections only, including z > 22.6, z > 23.1, r > 20.96, VT_B/VT_R > 21.5, and stacked VT_B/VT_R > 23.0 AB limits.
Redshift
What’s special vs typical
The event is notable because its short, soft high-energy emission and low Galactic latitude make a magnetar/SGR origin plausible, and the reported coordinates are coincident with EP J223759.5+531421. However, the circulars report no detected optical counterpart and no confirmed physical association beyond positional coincidence and follow-up context.