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"
28715 results found.
- GRB 220117C: Fermi GBM Observation
- GRB 220118A: 2.2m CAHA/CAFOS detections
- GRB 220118A: Fermi GBM detection
- GRB 220118A: COATLI Optical Observations
- GRB 220101A: KAO optical-R observation
- GRB 211221A: No V & R detection, KAO telescope
- GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
- GRB 220117C: Swift/BAT-GUANO arcminute localization
- Swift currently in safe hold with science slews disabled
- GRB 220118A: Swift-BAT refined analysis
- GRB 220118A: Swift/UVOT Detection
- Konus-Wind observation of the recent SGR 1935+2154 activity
- GRB 220118A: GIT optical observations
- GRB 220118A: MITSuME Akeno optical observation
- GRB 220117B: z-band limit
- Swift GRB 220118A: Global MASTER-Net observations report
- GRB 220117A: MITSuME Akeno optical upper limits
- Fermi GBM Sub-Threshold Detection of GRB 220117A
- GRB 220117B: Swift-BAT refined analysis
- GRB 220117A: Swift-BAT refined analysis
- GRB 220117B: Swift/UVOT Upper Limits
- GRB 220117A: Swift/UVOT Upper Limits
- GRB 220117A: LCO Optical Observations
- GRB 220117A: VLT/X-shooter optical afterglow and redshift
- Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
- GRB 220117B: Swift-XRT refined Analysis
- GRB 220117A: Swift-XRT refined Analysis
- GRB 220117B: Nanshan/NEXT optical upper limit
- GRB 220117B: MITSuME Akeno optical upper limits
- GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
- Swift GRB 220117A: Global MASTER-Net observations report
- Swift GRB 220117B: Global MASTER-Net observations report
- GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
- GRB 220101A: The most powerful GRB and BDHN I in 26 years
- GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
- AGILE observations of a burst from SGR 1935+2154
- GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
- GRB 220111A: AstroSat CZTI detection
- Fermi GRB 220111A: Global MASTER-Net observations report
- Konus-Wind detection of GRB 220101A (correction to GCN 31433)
- Konus-Wind detection of GRB 220101A
- GRB 220107A: SAO RAS optical observations
- Konus-Wind detection of GRB 220107B
- Konus-Wind detection of GRB 220107A
- Confirmation of the X-ray afterglow of GRB 220107B
- GRB 220107A: further SAO RAS optical observations
- GRB 220101A: Additional Liverpool telescope photometry
- GRB 220107A: SAO RAS optical observations
- GRB 220101A: SAO RAS optical observations
- GRB 220107A: AbAO and Terskol optical observations
- GRB 220107B: MITSuME Akeno optical upper limits
- GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
- GRB 220107A: Nanshan/NEXT optical observations
- GRB 220107A: Swift/UVOT Detection
- GRB 220107B: Fermi GBM observations
- GRB 220107A: MITSuME Akeno optical observation
- GRB 220107B: AstroSat CZTI detection
- GRB 220107B: Swift-XRT afterglow detection
- GRB 220107A: Swift-XRT afterglow detection
- GRB 220107A: AstroSat CZTI detection
- GRB 220107B: Tiled Swift observations
- GRB 220107A: Fermi GBM observations
- GRB 220107A: Swift ToO observations
- Fermi GRB 220107A: Global MASTER-Net observations report
- GRB 220107A: Swift/BAT-GUANO arcminute localization
- GRB 220101A: Tautenburg observations
- GRB 220101A: Continued Mondy optical observations
- GRB 220101A: further TNG NIR observations
- GRB 220101A: continued 1.3m DFOT Optical Observations
- GRB 220104A: Fermi GBM Observation
- GRB 220101A: Mondy optical observations
- GRB 220101A: 3rd LCO Optical Observation
- GRB 220101A: iTelescope optical observations
- GRB 211227A: Lijiang 2.4m Telescope Optical Observations
- GRB 220101A: VLA detection
- GRB 220101A: 1.3m DFOT observations
- GRB 220101A: LCO Continued Optical Observations
- GRB 220104A:GECAM detection
- Fermi GRB 220104A: Global MASTER-Net observations report
- GRB 211229B: Fermi GBM observation
- Fermi GRB 220103A: Global MASTER-Net observations report
- GRB 211227A: Gemini South Optical Observations
- GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220101A: TNG NIR afterglow detection
- GRB 220101A: ALMA detection
- GRB 220101A: LCO Optical Observations
- GRB 220101A: Tautenburg observations
- GRB 220101A: Swift-BAT refined analysis
- GRB 220101A: GMG observation (2nd epoch)
- GRB 211231A: AstroSat CZTI detection
- GRB 220101A: OASDG optical observations
- GRB 220101A : Eiso equals the maximum isotropic GRB energy
- GRB 220101A: GMG observation
- GRB 220101A: Asiago spectroscopic and photometric detection
- GRB220101A: optical afterglow detection from Konkoly Observatory
- GRB 220101A: Fermi GBM Detection
- GRB 220101A: NOT redshift confirmation
- GRB 220101A: CAHA 2.2m/CAFOS detection
- GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
- GRB 220101A: Swift-XRT refined Analysis