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.
Lucene Examples (click to copy):
subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
32085 results found.
- Fermi GRB 240112B: Global MASTER-Net observations report
- GRB 240109A: Swift-BAT refined analysis
- GRB 240112C: Swift detection of a burst with an optical counterpart
- GRB 240112B: Fermi GBM Final Real-time Localization
- GRB 240112A: GECAM detection of a burst
- GRB 240109A: Fermi GBM Observation
- GRB 240110A: AstroSat CZTI detection
- GRB 240108A: Glowbug gamma-ray detection
- GRB 231214A: ATCA Radio Upper Limits
- GRB 240106B: Glowbug gamma-ray detection
- GRB 240106A: Glowbug gamma-ray detection
- GRB 240109B: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240101C
- GRB 231215A: radio detection with the VLA
- GRB 230818A: further radio observations with the VLA
- GRB 230812B: further radio observations with the VLA
- GRB 240107A: AstroSat CZTI detection
- GRB 240109A: Swift detection of a short burst
- LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
- GRB 240106A: GRBAlpha detection
- GRB 240107A: MAXI/GSC detection
- GRB 240106B: Fermi GBM Final Real-time Localization
- GRB 240106A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 240101C (short)
- GRB GRB240101C: Fermi GBM observation
- GRB 240101A: 1.3m DFOT optical observations
- GRB 240102A: 1.3m DFOT optical upper limit
- GRB 240101B: 1.3m DFOT optical upper limit
- GRB 240101C: Swift/BAT-GUANO detection of a short burst
- GRB 240102C: AstroSat CZTI detection
- GRB 240101C: AstroSat CZTI detection
- GRB 231220A: Swift-UVOT upper limit
- GRB 240102A: Swift-BAT refined analysis
- GRB 240102A: Swift/UVOT Upper Limits
- GRB 231230A: Swift-BAT refined analysis
- GRB 240101A: Swift-BAT refined analysis
- GRB 240101B: Swift-BAT refined analysis
- GRB 240102A: Enhanced Swift-XRT position
- GRB 240101B: Swift-XRT refined Analysis
- GRB 240102A: Swift-XRT refined Analysis
- GRB 240102B (Fermi GBM trigger 725926335/240102925) is not a GRB
- GRB 240102A: LCOGT Optical Upper Limits
- GRB240102A: BOOTES-6/DPRT optical upper limit
- GRB 240102B: Fermi GBM Final Real-time Localization
- GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- GRB 240102A: Swift detection of a burst
- GRB 240101A: Terskol Zeiss-2000 optical observations
- GRB 240101C: GRBAlpha detection
- GRB 240101B: Swift/UVOT Upper Limits
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 240101A: Swift-XRT refined Analysis
- GRB 240101B: Enhanced Swift-XRT position
- GRB 240101B: KAIT Optical Upper Limit
- GRB 240101A: KAIT Optical Upper Limit
- GRB 240101A: Enhanced Swift-XRT position
- GRB 240101C: Fermi GBM Final Localization
- GRB 240101B: Swift detection of a burst
- GRB 240101A: Swift detection of a burst
- GRB231230A: Fermi GBM Observation
- GRB 231230A: Swift-XRT refined Analysis
- GRB 231230A: GOTO optical upper limits
- GRB 231230A: Enhanced Swift-XRT position
- GRB 231230A: Swift/UVOT Upper Limits
- GRB 231230A: NOT optical upper limits
- GRB 231230A: Prompt enhanced Swift-XRT position
- GRB 231230A: Swift detection of a burst
- GRB 231230A: Fermi GBM Final Real-time Localization
- GRB 231210B: BOOTES-7 optical upper limit
- LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
- IPN triangulation of GRB 231224A (short)
- GRB 231224A: Fermi GBM Final Real-time Localization
- GRB 231222B: GRBAlpha detection
- GRB 231222B: Swift-XRT afterglow detection
- GRB 231222B: Fermi GBM Detection
- GRB 231222B: Fermi-LAT detection
- GRB 231222A: Tiled Swift observations
- GRID detection of GRB 231215A
- GRB 231222A: Fermi GBM Final Real-time Localization
- GRB 231220A: Swift-XRT follow-up observations
- GRB 231220A: Swift ToO observations
- GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
- GRB 231220A: Fermi GBM Final Real-time Localization
- GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
- GRB 231219A: Fermi GBM Final Real-time Localization
- GRID detection of GRB 231205B
- GRID detection of GRB 231205A
- GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
- GRB 231214B: Fermi GBM observation
- GRB 231216A: optical upper limits from the INAF Asiago Observatory
- GRB 231216A: 10.4 m GTC optical upper limit
- GRB 231215A: AMI-LA radio detection
- GRB 231216A: Nanshan/HMT optical upper limit
- GRB 231216A: LCOGT Optical Upper Limits
- GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: Swift-XRT refined analysis correction
- GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
- GRB 231216A: Swift-XRT refined Analysis
- GRB 231216A: AST3-3 YaoAn Optical Upper Limit
- GRB 231216A: REM NIR upper limits
- GRB 231216A: Swift/UVOT Upper Limits