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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"19663 results found.
- Correction to GCN 28843: GBM report of GRB 201105B should have been GRB 201105A
- GRB 201104B: Swift/UVOT Detection
- GRB 201104B: Swift-XRT refined Analysis
- Correcton to GCN 28848: Swift observes ZTF20acozryr
- GRB 201104C: Swift ToO observations
- GRB 201105A: Swift detected burst and BAT refined analysis
- IPN triangulation of GRB 201103B (consistent with ZTF20acozryr/AT2020yxz)
- GRB 201104B: Swift-BAT refined analysis
- Swift Trigger 1004219: Detection of SGR 1830-0645
- GRB 201104A: Tiled Swift observations
- GRB 201104A: Fermi-LAT detection
- GRB 201104B: Swift/UVOT Detection
- GRB 201104B: MASTER optical observation
- GRB 201104B: Swift detection of a burst
- GRB 201015A: Late X-ray Detections with Chandra
- Swift GRB 201031A: Global MASTER-Net observations report
- Swift Trigger 1003313 (a.k.a. GRB 201031A) is not an astrophysical event
- GRB 201031A: Swift detection of a burst
- GRB 201029A: Swift-BAT refined analysis
- IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
- Swift GRB 201029A: Global MASTER-Net observations report
- GRB 201029A: Swift/UVOT Upper Limits
- GRB 201029A: Fermi GBM detection
- GRB 201029A: Swift-XRT refined Analysis
- GRB 201029A: BOOTES-1 optical upper limit
- GRB 201029A: Enhanced Swift-XRT position
- GRB 201029A: FRAM-ORM optical limit
- GRB 201029A: Swift detection of a burst
- GRB 201027A: MITSuME Akeno optical upper limits
- GRB 201027A: Swift-BAT refined analysis
- GRB 201026A: Swift-BAT refined analysis
- GRB 201027A: Swift/UVOT Upper Limits
- GRB 201027A: Swift-XRT refined Analysis
- GRB 201026A: Fermi GBM detection
- GRB 201026A: Swift-XRT refined Analysis
- GRB 201027A: 1.5m OSN optical upper limit
- GRB 201026A: Swift/UVOT Upper Limits
- GRB 201027A: Enhanced Swift-XRT position
- GRB 201026A: Enhanced Swift-XRT position
- GRB 201027A: Swift detection of a burst
- Swift GRB201027.05: Global MASTER-Net observations report
- GRB 201026A: Swift detection of a burst
- Swift GRB201026.94: Global MASTER-Net observations report
- GRB 201024A: 1.3m DFOT optical observations
- GRB 201020B: 1.3m DFOT continued optical follow-up observations
- GRB201024A: correction to GCN28777 - there was no rebrightening
- GRB 201024A: Swift-BAT refined analysis
- GRB201024A: rebrightening after initial steep decline
- GRB 201024A: Swift-XRT refined Analysis
- GRB 201024A: Swift/UVOT Detection
- GRB 201020B: 1.3m DFOT optical observations
- GRB 201024A: Enhanced Swift-XRT position
- GRB 200901A: FRAM-Auger optical limit
- GRB 201024A: BOOTES-2/TELMA early optical observation and 1.5m OSN follow-up
- GRB 201024A: Swift detection of a burst with an optical afterglow
- Swift GRB201024A: Global MASTER-Net OT detection
- Swift GRB201024.12: Global MASTER-Net observations report
- GRB 201021C: Swift-BAT refined analysis
- GRB 201021C: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
- Swift-XRT observations of IceCube 201021A (2)
- GRB 201021C: Fermi GBM detection
- GRB 201020A: GROWTH-India Telescope late-time optical upper limit
- GRB 201021C: Swift/UVOT Detection
- Konus-Wind detection of GRB 201020A
- GRB 201020B: Swift/UVOT Detection
- GRB 201020A: Swift/UVOT Observations
- GRB 201020B: Swift-XRT afterglow detection
- GRB 201021C: Enhanced Swift-XRT position
- GRB 201021C: MASTER optical synchronously observation
- Swift GRB201021.85: Global MASTER-Net observations report
- GRB 201021C: Swift detection of a burst with an optical counterpart
- Swift-XRT observations of IceCube 201021A
- GRB 201020B: Swift ToO observations
- GRB 201020A: Swift-XRT refined Analysis
- GRB 201020A: Fermi GBM observation
- GRB 201020A: Swift-BAT refined analysis
- Swift GRB 201020A: Global MASTER-Net observations report
- GRB 201014A: SAO RAS optical observations
- GRB 201020A: Enhanced Swift-XRT position
- GRB 201020A: Swift detection of a burst with an optical counterpart.
- GRB 201017A iTelescope observation
- GRB 201017A: GROWTH-India optical upper limit
- GRB 201014A: 3.6m DOT Optical Observations
- GRB 201013A: 3.6m DOT Optical Observations
- GRB 201014A: MMT afterglow detection
- GRB 201017A: MITSuME Akeno optical upper limits
- GRB 201017A: Swift-BAT refined analysis
- GRB 201015A: GROWTH-India Telescope (GIT) upper limit
- GRB 201015A: HCT optical photometric follow-up
- GRB 201017A: Assy and Mondy optical observations, possible afterglow detection
- GRB 201017A: Swift-XRT refined Analysis
- GRB 201015A: MMT afterglow imaging
- GRB 201017A: Fermi GBM detection
- GRB 201017A: Enhanced Swift-XRT position
- Trigger 1000631: Swift detection of Cen X-3
- GRB 201015A: classification as long GRB
- Swift GRB 201017A: Global MASTER-Net observations report
- GRB 201017A: Swift detection of a burst
- Fermi GBM Sub-Threshold Detection of GRB 201015A