GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"19666 results found.
- GRB 210222B: Swift-BAT refined analysis
- GRB 210222B: Swift-XRT refined Analysis
- GRB 210222B: Swift/UVOT Detection
- GRB 210222B: KAIT Optical Upper Limit
- GRB 210218A: Swift/UVOT observations
- GRB 210217A: Swift/UVOT Detection
- GRB 210222B: MASTER OT observation
- GRB 210222B: GOTO confirmation of afterglow detection
- GRB210222B: LCO Optical Afterglow Detection
- GRB210222B: BOOTES-1 optical afterglow detection
- GRB 210222B: Swift detection of a burst with an optical counterpart
- Swift GRB210222.94: Global MASTER-Net observations report
- GRB 210218A: Swift-XRT observations
- GRB 210212A: Lowell Discovery Telescope observations
- GRB 210217A: 1.3m DFOT optical detection
- GRB 210217A: Swift-XRT refined Analysis
- GRB 210218A: Swift-BAT refined analysis
- Fermi GBM Sub-Threshold Detection of GRB 210217A
- GRB 210217A: Liverpool Telescope First Hour Observations
- GRB 210217A: Swift-BAT refined analysis
- GRB 210217A: KAIT Optical Observations
- GRB 210218A: MITSuME Akeno optical upper limits
- GRB 210218A: GWAC-F60A optical upper limit
- GRB 210218A: NEXT optical upper limit
- GRB 210218A: Swift detection of a burst
- GRB 210205A: observations with the 3.6m DOT, a potential dark burst?
- GRB 210217A: Enhanced Swift-XRT position
- Fermi/GBM observation of a burst from SGR 1830-0645
- GRB 210217A: NEXT early optical afterglow observations
- GRB 210217A: Swift detection of a burst with an optical counterpart
- GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
- Swift Trigger 1033144: Detection of SGR 1830-0645
- GRB 210212B: Swift ToO observations
- IPN triangulation of GRB 210212B (consistent with ZTF21aakruew/AT2021cwd)
- GRB 210212A: 1.3m DFOT Optical upper limit
- GRB 210212A: Gemini South optical observations
- Swift Trigger 1032350: Detection of SGR 1830-0645
- GRB 210212A: Possible host galaxy counterpart with the NOT
- Swift GRB 210212A: Global MASTER-Net observations report
- GRB 210212A: MITSuME Akeno optical upper limits
- GRB 210212A: Swift-XRT refined Analysis
- GRB 210212A: BOOTES-4/MET optical upper limit
- GRB 210212A: Swift/UVOT Upper Limits
- GRB 210212A: Swift-BAT refined analysis
- GRB 210212A: Enhanced Swift-XRT position
- GRB 210212A: Swift detection of a burst
- GRB 210207B: GECAM detection
- GRB 210211A: Swift/UVOT Detection
- GRB 210211A: Swift-XRT refined Analysis
- GRB 210211A: Swift-BAT refined analysis
- GRB 210211A: Fermi GBM observation
- Swift-XRT observations of IceCube-210210A
- GRB 210209A: Swift-BAT refined analysis
- GRB 210211A: Enhanced Swift-XRT position
- GRB 210211A: MASTER optical observation of REM OT
- GRB 210211A: Swift detection of a burst
- Swift GRB210211.36: Global MASTER-Net observations report
- GRB 210210A: Swift-BAT refined analysis
- GRB 210209A: BOOTES-4/MET optical upper limit
- GRB 210210A: LCO Optical Afterglow Detection
- Swift GRB 210209A: Global MASTER-Net observations report
- GRB 210210A: Swift/UVOT Detection
- GRB 210209A: MITSuME Akeno optical upper limits
- GRB 210209A: Swift/UVOT Upper Limits
- GRB 210210A: Swift-XRT refined Analysis
- GRB 210210A: Redshift from OSIRIS/GTC
- GRB 210209A: Swift-XRT refined Analysis
- GRB 210210A: Enhanced Swift-XRT position
- GRB 210210A: MASTER afterglow observation
- Swift GRB 210210A: Global MASTER-Net observations report
- GRB 210210A: Swift detection of a burst with an optical counterpart
- GRB 210209A: Enhanced Swift-XRT position
- GRB 210209A: Swift detection of a burst
- GRB 210207B: Continued LCO Observations
- GRB 210207B: AstroSat CZTI detection
- GRB 210207B: Swift/UVOT Detection
- GRB 210207B: Swift-BAT refined analysis
- GRB 210207B: Insight-HXMT/HE detection
- GRB 210207B: LCO Optical Afterglow Detection
- GRB 210207B: KAIT Optical Observations
- GRB 210207B: AGILE observations
- GRB 210207B: Swift-XRT refined Analysis
- Konus-Wind detection of GRB 210207B
- GRB 210207B: Enhanced Swift-XRT position
- GRB 210207B: optical detection with 3.6m Devasthal Optical Telescope
- GRB 210207B: Swift detection of a burst with a bright optical counterpart
- GRB 210204A / ZTF21aagwbjr: Swift-XRT observations
- GRB 210204A: Swift ToO observations
- GRB 210205A: Swift-BAT refined analysis
- IPN triangulation of GRB 210204A
- GRB 210205A: Swift-XRT refined Analysis
- GRB 210205A: MITSuME Ishigaki optical observation
- GRB 210205A: Swift/UVOT Upper Limits
- Swift GRB 210205A: Global MASTER-Net observations report
- GRB 210205A: BOOTES-4/MET optical upper limit
- GRB 210205A: Enhanced Swift-XRT position
- GRB 210205A: Swift detection of a burst
- GRB 210202A: Fermi-LAT detection
- Fermi GBM Observations of SGR J1935+2154
- GRB 140330A: Swift-XRT refined Analysis