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"3296 results found.
- GRB 260706A: REM optical/NIR observations
- GRB 260706A: LCO optical upper limit
- GRB 260706A: EP-FXT follow-up observation
- The EP-WXT trigger 01709274151 is likely a flaring star
- The EP-WXT trigger 01709274141 is likely a flaring star
- The EP-WXT trigger 01709274014: KAIT confirmation of a stellar flare
- The EP-WXT trigger 01709274014 is likely a flaring star
- GRB 260704A: NOT optical upper limits
- GRB 260704A: EP-FXT follow-up observation
- EP260703a: EP-FXT follow-up observation
- EP260703a: EP-WXT detection of a fast X-ray transient
- EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
- EP260628a: EP-FXT follow-up observation
- EP260628a: EP-WXT detection of a fast X-ray transient
- The EP-WXT trigger 01709272671 is likely a flaring star
- EP260626a: further Liverpool Telescope optical upper limits
- EP260626a: EP-FXT follow-up observation
- EP260626a: COLIBRÍ optical upper limit
- EP260626a: Liverpool Telescope upper limits
- EP260626a: EP-WXT detection of a fast X-ray transient
- Konus-Wind detection of GRB 260623B / EP260623a
- EP260623a: TNG NIR afterglow detection
- GRB 260618A: Fermi GBM Observation
- MASS-Cube (GRID 2.0) detection of GRB 260616B
- EP260623a: Liverpool Telescope optical observations
- Konus-Wind detection of GRB 260618B
- EP260623a:refined analysis of the EP-WXT and EP-FXT observation
- EP260623a: WINTER J-band observations
- EP260623a: Optical follow-up observations with Kinder
- EP260623a: TRT optical observations
- EP260623a: REM optical/NIR afterglow detection
- EP 260623a: COLIBRÍ optical observations
- EP260623a: OSIRIS+/GTC redshift z = 0.703
- EP260623a: Las Cumbres discovery of the optical counterpart
- EP260623a: Einstein Probe detection of an X-ray transient
- GRB 260614B: EP-FXT follow-up observation
- EP260618a: Liverpool Telescope optical observations
- The EP-WXT trigger 01709271197 is likely a flaring star
- EP260618a: JinShan optical observations
- GRB 260616B/EP260616a: SVOM/GRM detection of a burst
- Konus-Wind detection of GRB 260617A
- GRB 260616B: AstroSat CZTI detection
- EP260618a: EP-FXT follow-up observation
- EP260618a: EP-WXT detection of an X-ray transient
- EP260616a/GRB 260616B: EP-FXT follow-up observation
- Konus-Wind detection of GRB 260616B/EP260616a
- Konus-Wind detection of GRB 260616A
- GRB 260616B: CALET Gamma-Ray Burst Monitor detection
- EP260616a/GRB260616B: COLIBRÍ optical upper limit
- EP260616a: EP-WXT detection of a fast X-ray transient
- The EP-WXT trigger 01709270148 is likely a flaring star
- The EP-WXT trigger 01709269893 is likely a flaring star
- The EP-WXT trigger 01709269488 is likely a flaring star
- EP260605a: COLIBRÍ optical upper limits
- IceCube-260610A: EP-FXT follow-up observation
- The EP-WXT trigger 01709269176: SVOM/C-GFT confirmation of a stellar flare
- EP260610b: GTC likely spectroscopic redshift z = 1.10
- The EP-WXT trigger 01709269176 is likely a flaring star
- EP260610b: refined analysis of the EP-WXT and follow-up EP-FXT observations
- EP260610a: refined analysis of the EP-WXT and follow-up EP-FXT observations
- EP260610b: MAO/AZT-22 optical observations
- EP260610b: NOT optical observation
- EP260610a: SVOM/VT optical upper limits
- EP260610b: Einstein Probe detection of an X-ray transient
- Konus-Wind detection of GRB 260601A
- EP260610a: COLIBRÍ optical upper limits
- EP260610a: Einstein Probe detection of a fast X-ray transient
- Konus-Wind detection of GRB 260604C
- Konus-Wind detection of GRB 260607B
- EP260605a: EP-FXT follow-up observation
- EP260605a: Einstein Probe detection of a fast X-ray transient
- The EP-WXT trigger 01709267001 is likely a flaring star
- EP260602d: EP-FXT follow-up observation
- EP260602c: EP-FXT follow-up observation
- The EP-WXT trigger 01709266798 is likely a flaring star
- EP260602d: J-band upper limit with WINTER
- EP260602b: J-band upper limit with WINTER
- EP260602a: EP-FXT follow-up observation
- EP260603a: Global MASTER-Net observations report
- EP260603a: Einstein Probe detection of a fast X-ray transient
- EP260602d: Optical Upper limits with kinder observations
- Konus-Wind detection of GRB 260601B/EP260601a
- GRB 260603A: EP-FXT follow-up observation
- EP260601a/GRB 260601B: EP-FXT follow-up observation
- EP260602b: EP-FXT follow-up observation
- EP260602a: NOT NIR J-band observations
- EP260602d: Einstein Probe detection of a fast X-ray transient
- EP260602c: Einstein Probe detection of a fast X-ray transient
- EP260602b: Einstein Probe detection of a fast X-ray transient
- GRB 260601B/EP260601a: Insight-HXMT detection
- EP-WXT trigger 01709266414 (EP260602b): JinShan optical counterpart detection
- GRB 260601B: CALET Gamma-Ray Burst Monitor detection
- EP260602a: Optical upper limits with Kinder observations
- GRB 260601B / EP260601a: NuSTAR detection of prompt emission
- EP260602a: Einstein Probe detection of a fast X-ray transient
- GRB 260601B/EP260601a: GECAM-B analysis suggests a possible long duration Type I burst
- GRB 260601B: GECAM-B detection of a burst probably associated with EP260601a
- EP260601a: Einstein Probe detection of an X-ray transient
- EP-WXT trigger 01709266307 (EP260601a): COLIBRÍ optical observations
- EP-WXT trigger 01709266307 (EP260601a): JinShan optical counterpart detection