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"21468 results found.
- GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
- Swift J1913.1+1946: Early Optical Photometry
- GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
- GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
- GRB 221009A (Swift J1913.1+1946): Mondy optical observations
- GRB 221009A BOOTES-2/TELMA and OSN optical detections
- Swift J1913.1+1946 : Pre-discovery limits from ZTF
- GRB 221009A: Fermi GBM observation
- IPN triangulation of extremely bright GRB 221009A
- Swift J1913.1+1946: Optical photometry
- Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
- GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
- GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
- GRB 221009A: Swift detected transient may be GRB
- Swift GRB221009.59: Global MASTER-Net OT detection
- GRB 221008A: Swift-XRT observations
- Swift J1913.1+1946 a new bright hard X-ray and optical transient
- GRB 221008A: Tiled Swift observations
- GRB 221006A: Swift-XRT observations
- GRB 221006A: Tiled Swift observations
- GRB 220930A: MITSuME Akeno optical upper limits
- GRB 220930A: AbAO Optical Upper Limit
- Konus-Wind detection of GRB 220930A
- GRB 220930A: AstroSat CZTI detection
- GRB 220930A: Swift-BAT refined analysis
- GRB 220930A: Swift-XRT refined Analysis
- GRB 220930A: LCOGT Optical Upper Limits
- GRB 220930A: Swift/UVOT Upper Limits
- GRB 220930A: Enhanced Swift-XRT position
- Swift GRB 220930A: Global MASTER-Net observations report
- GRB 220930A: BOOTES-5/JGT early optical upper limit
- GRB 220930A: Prompt enhanced Swift-XRT position
- GRB 220930A: COATLI Upper Limits
- GRB 220930A: Swift detection of a burst
- IPN triangulation of GRB 220927A (long)
- GRB 220924A: Fermi GBM detection
- Swift Trigger 1125354 (GRB 220926A) is not a GRB
- Swift GRB220926.34: Global MASTER-Net observations report
- Swift GRB 220926A: Global MASTER-Net observations report
- GRB 220926A: Swift detection of a burst
- GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
- Swift GRB220923.47: Global MASTER-Net observations report
- GRB 220921A: MeerLICHT afterglow observations
- GRB 220921A: Swift-XRT Observations
- GRB 220921A: Fermi-LAT detection
- GRB 220921A: Tiled Swift observations
- GRB 220909A: Fermi GBM observation
- GRB 220909A: Swift-XRT observations
- IPN triangulation of GRB 220905A
- GRB 220909A: Swift ToO observations
- GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
- GRB 220907A: Swift-BAT refined analysis
- GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
- IPN triangulation of GRB 220903A (long)
- GRB 220907A: Fermi GBM observation
- GRB 220907A: Nanshan/NEXT optical upper limits
- GRB 220907A: Swift/UVOT Upper Limits
- GRB 220907A: Swift-XRT refined Analysis
- GRB 220831A: ATCA 5/9 GHz radio observations
- GRB 220907A: Swift-XRT position
- GRB 220907A: Swift detection of a burst
- Swift GRB220907.59: Global MASTER-Net observations report
- GRB 220831A: Swift-UVOT Upper Limits
- GRB 220831A: DECam detection of a possible optical counterpart
- GRB 220831A, VLT/HAWK-I near-infrared observations
- GRB 220831A: Fermi GBM observation
- GRB 220831A: Swift-XRT observations
- GRB 220831A: Swift ToO observations
- GRB 220831A: Swift/BAT-GUANO localization of a short burst
- Konus-Wind detection of GRB 220826A
- GRB 220826A: Swift-BAT refined analysis
- GRB 220826A: Fermi GBM observation
- GRB 220826A: Swift-XRT refined Analysis
- GRB 220825A: Fermi GBM observation
- GRB 220826A: Lesedi optical afterglow detection
- GRB 220826A: Swift/UVOT Detection
- Swift GRB 220826A: Global MASTER-Net observations report
- GRB 220826A: Enhanced Swift-XRT position
- GRB 220826A: Swift detection of a burst with an optical counterpart
- GRB 220825A: Swift/BAT-GUANO detection
- GRB 220823A: Fermi GBM detection
- GRB 220823A: Swift/BAT-GUANO detection of a short burst
- Konus-Wind detection of GRB 220813A
- GRB 220813A: VLT optical observations and possible host galaxy
- GRB 220813A: Swift/UVOT Detection
- GRB 220810A: Further Swift-XRT observations
- GRB 220813A: Swift-XRT refined Analysis
- Swift GRB 220813A: Global MASTER-Net observations report
- GRB 220813A: Enhanced Swift-XRT position
- GRB 220813A: Swift detection of a burst with an optical counterpart
- GRB 220810A: Swift-XRT observations
- GRB 220810A: Swift ToO observations
- GRB 220806A: Swift-BAT refined analysis
- GRB 220806A: Swift detection of a burst
- Swift GRB220806.76: Global MASTER-Net observations report
- Konus-Wind detection of GRB 220730A (short)
- GRB 220730A: Swift-BAT refined analysis
- GRB 220730A: Fermi GBM detection
- GRB 220730A: Swift-XRT afterglow detection
- GRB 220730A: Swift/UVOT Upper Limits