GRB 260330B

General information

GRB 260330B was triggered and localized by SVOM/ECLAIRs at 2026-03-30 14:19:57 UTC, with additional prompt detection by SVOM/GRM and a sub-threshold transient found by Fermi/GBM targeted search. EP-FXT follow-up identified a fading X-ray afterglow and SVOM/VT reported a faint optical candidate consistent with the X-ray position.

Wavelength coverage

Gamma-ray: SVOM/ECLAIRs trigger/localization and refined spectral analysis; SVOM/GRM detection; Fermi/GBM targeted-search sub-threshold transient reported (44157, 44159, 44210).
X-ray: EP-FXT detected multiple sources in the ECLAIRs region and identified a fading afterglow candidate with 10 arcsec error radius; SVOM/MXT reported no X-ray observation at the time of the initial notice (44157, 44203).
Optical: LCO and SVOM/VT report early upper limits; later SVOM/VT ToO reports a faint candidate at the EP-FXT afterglow position with VT_R measurements (44158, 44168, 44205). No radio, near-IR, UV, TeV, neutrino, or GW observations are mentioned.

Lightcurve and spectrum

Redshift

What’s special vs typical

GCN 44210: GRB 260330B: SVOM/ECLAIRs refined analysis

2026-04-03T19:30:32.225Z | rev 0

GCN 44205: GRB 260330B: SVOM/VT optical candidate

2026-04-03T12:11:54.444Z | rev 0

GCN 44203: GRB 260330B: EP-FXT follow-up and identification of candidate afterglow

2026-04-03T10:26:00.527Z | rev 0

GCN 44168: GRB 260330B: SVOM/VT optical upper limits

2026-03-31T15:25:54.249Z | rev 0

GCN 44159: Fermi GBM Sub-Threshold Detection of GRB 260330B

2026-03-30T19:48:13.025Z | rev 0

GCN 44158: GRB 260330B: LCO optical upper limits

2026-03-30T18:58:32.131Z | rev 0

GCN 44157: GRB 260330B: SVOM detection of a burst

2026-03-30T14:50:52.860Z | rev 0