General information
GRB 260208A triggered Fermi/GBM at 2026-02-08 05:07:28 UT and is reported as a likely long GRB (T90 ~35–38 s). A multi-instrument counterpart is identified at RA=204.7315 deg, Dec=+33.80112 deg (J2000) consistent across optical, X-ray, and radio reports.
Wavelength coverage
- Gamma-ray: Detected by Fermi/GBM; high-energy emission detected by Fermi/LAT; also detected by GECAM-B, NuSTAR SINGS shields, Glowbug (ISS), and TERI (ISS).
- X-ray: Swift/XRT detected an uncatalogued source consistent with the optical transient.
- UV: Swift/UVOT detected the afterglow (white, u, v).
- Optical: Multiple detections (MASTER, GOTO, ZTF, SVOM/VT, Liverpool Telescope, NOT acquisition/spectroscopy, COLIBRÍ, ARIES DFOT, Mondy, LCO).
- Radio: VLA detected an unresolved source at 6/10/15 GHz.
No observations were mentioned in the provided text for IR, sub-mm/mm, or TeV.
Lightcurve and spectrum
Redshift
Spectroscopic redshift z=2.36 measured by NOT from a Lyα absorption trough at 4080 Å and multiple metal absorption features.
What’s special vs typical
Fermi/LAT reports >100 MeV emission with a highest-energy photon of 5.3 GeV at 1168 s post-trigger, and the afterglow is confirmed from UV/optical through radio with a secure spectroscopic redshift.
GCN 43952: GRB 260208A: radio detection with the VLA
2026-03-10T09:40:09.634Z | rev 0
GCN 43896: GRB 260208A: TERI Gamma-ray detection
2026-03-02T15:52:13.543Z | rev 0
GCN 43771: GRB 260208A: AbAO and Terskol optical upper limits
2026-02-17T14:19:08.591Z | rev 0
GCN 43770: GRB 260208A: continued Mondy optical observations
2026-02-17T14:07:31.343Z | rev 0
2026-02-11T17:42:26.995Z | rev 2
GCN 43694: GRB 260208A: LCO detection of the optical counterpart
2026-02-11T12:33:24.764Z | rev 0
GCN 43676: GRB260208A: Liverpool Telescope optical follow-up observations
2026-02-10T00:51:14.058Z | rev 2
GCN 43676: GRB260208A: Liverpool Telescope optical follow-up observations
2026-02-10T00:51:14.058Z | rev 0
GCN 43675: GRB 260208A: Glowbug gamma-ray detection
2026-02-09T23:42:07.775Z | rev 0
GCN 43674: GRB 260208A: NuSTAR detection of prompt emission
2026-02-09T21:01:46.769Z | rev 0
GCN 43673: GRB 260208A: Fermi GBM Observation
2026-02-09T20:09:35.373Z | rev 0
GCN 43673: GRB 260208A: Fermi GBM Observation
2026-02-09T20:09:35.373Z | rev 2
GCN 43667: GRB 260208A: Mondy optical observations
2026-02-09T12:00:08.157Z | rev 0
GCN 43667: GRB 260208A: Mondy optical observations (duplicate submission)
2026-02-09T12:00:08.157Z | rev 2
GCN 43666: GRB 260208A: Mondy optical observations
2026-02-09T11:57:27.085Z | rev 0
GCN 43665: GRB 260208A: 1.3m DFOT optical detection
2026-02-09T11:24:07.318Z | rev 0
GCN 43664: GRB 260208A: COLIBRÍ optical observations
2026-02-09T11:14:54.224Z | rev 0
GCN 43662: GRB 260208A: NOT spectroscopic redshift z = 2.36
2026-02-09T10:13:18.879Z | rev 0
GCN 43661: GRB 260208A: Liverpool Telescope optical detection
2026-02-09T10:00:09.741Z | rev 0
GCN 43658: GRB 260208A: GECAM-B observation of a bright burst
2026-02-09T05:50:39.440Z | rev 2
GCN 43658: GRB 260208A: GECAM-B observation of a bright burst
2026-02-09T05:50:39.440Z | rev 0
GCN 43657: GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
2026-02-09T03:44:52.819Z | rev 0
GCN 43655: GRB 260208A: SVOM/VT optical observation
2026-02-09T02:31:49.461Z | rev 0
GCN 43652: GRB 260208A: Swift-XRT observations
2026-02-08T21:51:33.855Z | rev 0
2026-02-08T15:21:39.654Z | rev 0
GCN 43643: GRB 260208A: Swift ToO observations
2026-02-08T14:50:32.684Z | rev 0
GCN 43642: GRB 260208A: Fermi GBM Classification Correction
2026-02-08T14:07:05.884Z | rev 0
GCN 43641: GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)
2026-02-08T14:01:53.356Z | rev 0
GCN 43640: GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
2026-02-08T12:35:14.305Z | rev 0
GCN 43637: Fermi GRB 260208A: Global MASTER-Net observations report
2026-02-08T06:45:32.978Z | rev 0
GCN 43635: GRB 260208A: Fermi GBM Final Real-time Localization
2026-02-08T05:18:10.811Z | rev 0