GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"15247 results found.
- IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260705A: SVOM/ECLAIRs refined analysis
- GRB 260706A: SVOM detection of a burst
- The EP-WXT trigger 01709274014 is likely a flaring star
- GRB 260704A: NOT optical upper limits
- GRB 260705A: SVOM detection of a burst
- GRB 260629A: SVOM/GRM observation of a short burst
- GRB 260629A: GECAM-A observation of a short burst
- IceCube-260704A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 260629A: AstroSat CZTI detection
- GRB 260704A: SVOM detection of a possible GRB
- Fermi-LAT Gamma-ray Observations of IceCube-260622A
- EP260626a: further Liverpool Telescope optical upper limits
- EP260626a: COLIBRÍ optical upper limit
- Konus-Wind detection of GRB 260623B / EP260623a
- GRB 260618A: Fermi GBM Observation
- GRB 260619A: SVOM/ECLAIRs refined analysis
- EP260623a: Liverpool Telescope optical observations
- Konus-Wind detection of GRB 260618B
- IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
- EP260623a: Optical follow-up observations with Kinder
- EP260623a: FRAM-ORM detection of the optical afterglow rise, peak and decay
- EP 260623a: COLIBRÍ optical observations
- GRB 260616B/EP260616a: Insight-HXMT/HE detection
- IceCube-260622A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
- EP260618a: Liverpool Telescope optical observations
- GRB 260619A: NOT optical observations
- EP260618a: JinShan optical observations
- GRB 260616B/EP260616a: SVOM/GRM detection of a burst
- GRB 260618B: Fermi GBM Observation
- IceCube-Cascade 260618A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260619A: TRT optical counterpart confirmation
- GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
- GRB 260604B: 239Alferov CubeSat detection
- GRB 260604A: 239Alferov CubeSat detection
- GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
- Fermi-LAT Gamma-ray Observations of IceCube-260610A
- Konus-Wind detection of GRB 260617A
- GRB 260616B: AstroSat CZTI detection
- GRB 260616A: AstroSat CZTI detection
- GRB 260616A: SVOM/GRM observation
- EP260618a: LCO optical counterpart confirmation
- GRB 260617A: CALET Gamma-Ray Burst Monitor detection
- GRB 260619A: SVOM possible detection of a faint burst
- IceCube-260610A: Upper limits from a search for additional neutrino events in IceCube
- GRB 260618B: Fermi-LAT detection
- GRB 260610B/AT 2026owq: FTW optical and NIR observations
- GRB 260616A: Insight-HXMT detection
- EP260618a: EP-WXT detection of an X-ray transient
- GRB 260506B: cubesat Avion detection
- GRB 260616C: GECAM-B observation of a burst
- GRB 260617A: Fermi GBM Detection
- Konus-Wind detection of GRB 260616B/EP260616a
- Konus-Wind detection of GRB 260616A
- GRB 260616B: CALET Gamma-Ray Burst Monitor detection
- GRB 260616A: GECAM-B observation
- GRB 260429A: cubesat Avion detection
- GRB 260616A: Fermi-LAT detection
- GRB 260610B / AT 2026owq: COLIBRÍ further observations and confirmation of the rebrigthening
- GRB 260614A: AstroSat CZTI detection
- GRB 260614B: SVOM/ECLAIRs refined analysis
- GRB 260614B: GECAM-B observation
- GRB 260610B: SVOM/GRM observation
- GRB 260614B: Fermi GBM Observation
- GRB 260614A: GECAM-B observation
- GRB 260614B: SVOM detection of a burst
- GRB 260611B: SVOM/GRM detection
- GRB 260603C: AstroSat CZTI detection
- GRB 260610B: further Liverpool Telescope optical observations
- GRB 260610B: Fermi GBM Observation
- GRB 260610B / AT2026owq: GRANDMA optical observations
- GRB 260610b: Liverpool Telescope optical observations
- IceCube-260610A: No candidates from the Zwicky Transient Facility
- GRB 260611B: CALET Gamma-Ray Burst Monitor detection
- The EP-WXT trigger 01709269176: SVOM/C-GFT confirmation of a stellar flare
- GRB 260610B / AT2026owq: OASDG optical observations
- GRB 260610B: optical counterpart shows spectroscopic redshift of z=0.473
- GRB 260610B / AT 2026owq: COLIBRÍ optical observations
- GRB 260610B / AT2026owq: Early ATLAS observations
- GRB 260610B: TRT optical observation
- EP260610a: refined analysis of the EP-WXT and follow-up EP-FXT observations
- EP260610b: COLIBRÍ optical observations
- GRB 260610B: DDOTI optical observations
- EP260610b: NOT optical observation
- IceCube-260610A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 260515A: SOAR optical observations
- Konus-Wind detection of GRB 260601A
- Konus-Wind detection of GRB 260604C
- GRB 260608A: Fermi GRB Observation
- GRB 260604C: AstroSat CZTI detection
- GRB 260604C: SVOM/ECLAIRs refined analysis
- GRB 260608A: SVOM/ECLAIRs refined analysis
- Konus-Wind detection of GRB 260607B
- GRB 260607B: GECAM-B observation
- GRB 260607A / GOTO26fqf / AT2026ong: COLIBRÍ optical observations
- GRB 260604C: SVOM/COLIBRÍ (FM-GFT) colour evolution and confirmation of the late rebrightening
- GRB 260607B: AstroSat CZTI detection
- GRB 260608A: SVOM detection of a burst
- GRB 260607A: TRT optical observations