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.
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"26042 results found.
- GRB 220606B: Swift follow-up observations
- GRB 220606A: Swift/BAT-GUANO detection
- GRB 220606B: GUANO coordinate correction to GCN 32167
- GRB 220527A: A BdHN I with a clear UPE phase
- GRB 220606B: Swift ToO observations
- GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
- GRB 220603A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220527A: MITSuME Akeno continued optical observation
- GRB 220527A: Lick 3m Optical Observations
- Konus-Wind detection of GRB 220528A
- IPN triangulation of GRB 220528A (short)
- GRB 220528A: Fermi GBM Observation
- Trigger 1108538: Swift detection of a burst from SGR J1935+2154
- Swift trigger 1108515 is not an astrophysical event
- Correction to GCN 32148: Should be GRB 220528A
- GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220527A: AST3-3 Yaoan Optical Observation
- GRB 220527A: REM optical/NIR observations
- GRB 220527A: VLT/X-shooter spectroscopic redshift
- GRB 220527A: MeerLICHT afterglow observations
- GRB 220527A: NOT optical photometry and spectroscopic redshift
- GRB 220527A: AstroSat CZTI detection
- GRB 220527A: MITSuME Akeno optical observation
- GRB 220527A: Swift/UVOT detection
- GRB 220527A: Swift-XRT afterglow detection
- Swift trigger 1108208 is not an interesting astrophysical event.
- GRB 220527A: Swift ToO observations
- Swift GRB220526.48: Global MASTER-Net observations report
- IPN triangulation of GRB 220524A
- GRB 220521A: BOOTES-2/TELMA and CAHA 2.2m telescope optical upper limit
- GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
- GRB 220521A: ISON-Castelgrande observatory optical observations
- GRB 220521A: MITSuME Akeno optical upper limits
- GRB 220521A: Gemini Observations
- GRB 220521A: MMT Afterglow Imaging
- GRB 220521A: REM optical/NIR upper limits
- GRB 220514A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220521A: LCO Optical Detection
- GRB 220521A: Swift-BAT refined analysis
- GRB 220521A: Fermi GBM detection
- GRB 220521A: Sintesz-Newton/CrAO optical upper limit
- GRB 220521A: RATIR Optical and NIR Observations
- GRB 220521A: Swift-XRT refined Analysis
- GRB 220521A: Swift/UVOT Upper Limits
- GRB 220521A: Enhanced Swift-XRT position
- GRB 220521A: NOT optical afterglow detection
- GRB 220521A: Prompt enhanced Swift-XRT position
- GRB 220521A: Swift detection of a burst
- Swift GRB220521.97: Global MASTER-Net observations report
- Swift BAT Trigger 1107209 is not an astrophysical event
- GRB 220518A: Swift-BAT refined analysis
- Swift GRB220519.84: Global MASTER-Net observations report
- GRB 220518A: Swift-XRT refined Analysis
- GRB 220518A: Swift/UVOT Detection
- GRB 220518A: Enhanced Swift-XRT position
- Swift GRB 220518A: Global MASTER-Net observations report
- GRB 220518A: Swift detection of a burst
- GRB 220514A: MITSuME Akeno optical observation
- GRB 220514A: GRANDMA Optical Afterglow Observations
- GRB 220514B: Swift-XRT observations
- GRB 220511A: Swift-XRT afterglow detection
- GRB 220514A: KAIT Optical Afterglow Confirmation
- GRB 220514B: Tiled Swift observations
- GRB 220514A: MeerLICHT optical afterglow candidate
- GRB 220427A: MeerLICHT afterglow observations
- GRB 220511A: Fermi GBM observation
- GRB 220511A: Swift-XRT observations
- GRB 220511A: AstroSat CZTI detection
- GRB 220511A: BOOTES-2/TELMA optical upper limit
- GRB 220511A: Swift ToO observations
- GRB 220511A: Swift/BAT-GUANO arcminute localization
- GRB 220506A: MITSuME Akeno optical upper limits
- GRB 220506A: GIT optical upper limit.
- GRB 220506A: BOOTES-5/JGT optical upper limit
- GRB 220506A: Swift-XRT afterglow detection
- GRB 220506A: Tiled Swift observations
- Swift-BAT triggers 1105560-1 are not GRBs
- Swift GRB220506.51: Global MASTER-Net observations report
- GRB 220430A: Nanshan/NEXT optical upper limit
- GRB 220430A: Nanshan/HMT optical upper limit
- GRB 220430A: GIT optical upper limits
- IPN triangulation of GRB 220423A
- GRB 220427A: LCO Optical Observations
- GRB 220501A: Swift-BAT refined analysis
- GRB 220427A: GRANDMA Early Optical Afterglow Detection
- GRB 220501A: BOOTES-1 optical upper limit
- GRB 220501A: Fermi GBM observation
- GRB 220430A: AstroSat CZTI detection
- GRB 220501A: Swift detection of a burst
- GRB 220430A: Swift-BAT refined analysis
- GRB 220430A: CAHA 2.2m telescope optical limit
- GRB 220430A: Swift-XRT refined Analysis
- Swift GRB 220430A: Global MASTER-Net observations report
- GRB 220430A: GRANDMA observations
- GRB 220430A: Mondy and AbAO optical upper limits
- GRB 220430A: AGILE detection
- GRB 220430A: MeerLICHT optical upper limits
- GRB 220430A: Enhanced Swift-XRT position
- GRB 220430A: Swift detection of a burst or Swift J0630.4+0932
- GRB 220427A: Swift-BAT refined analysis