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"27402 results found.
- Fermi GRB 220623B: Global MASTER-Net observations report
- IPN triangulation of GRB 220624A
- GRB 220623A: Swift-BAT refined analysis
- GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220624A: AGILE/GRID analysis
- GRB 220623A: AbAO optical upper limit
- GRB 220623A: Swift-XRT refined Analysis
- GRB 220623A: NOT optical observations
- GRB 220623A: Swift/UVOT Upper Limits
- GRB 220623A: BOOTES-5/JGT optical afterglow detection
- GRB 220623A: Enhanced Swift-XRT position
- GRB 220623A: AstroSat CZTI detection
- GRB 220623A: iTelescope optical upper limit
- GRB 220623A: Swift-XRT observations
- GRB 220618A: Fermi GBM detection
- GRB 220618A: Swift-BAT refined analysis
- GRB 220618A: iTelescope T-19 upper limit
- GRB 220617A: TNG optical observations
- GRB 220617A: Fermi GBM observation
- Swift Trigger 1110865 is probably not an astrophysical event
- GRB 220618A: Swift-XRT refined Analysis
- GRB 220618A: Swift/UVOT Upper Limits
- GRB220611A: Gemini Optical Afterglow Confirmation
- GRB 220618A: Enhanced Swift-XRT position
- GRB 220617A: Swift-XRT observations
- GRB 220618A: Swift detection of a burst
- GRB 220611A: Swift/UVOT Upper Limits
- GRB 220612A: Swift/BAT-GUANO detection
- GRB 220608B: Detection by VZLUSAT-2
- GRB 220611A: Swift-XRT refined Analysis
- GRB 220611A: Enhanced Swift-XRT position
- GRB 220611A: Swift detection of a burst
- Fermi trigger No 676537486: Global MASTER-Net observations report
- GRB 220609B: AstroSat CZTI detection
- Fermi trigger No 676366592: Global MASTER-Net observations report
- GRB 220608A: AstroSat CZTI detection
- GRB 220606A: Fermi GBM observation
- Fermi GRB 220608A: Global MASTER-Net observations report
- GRB 220606B: Gemini South Optical Observations
- MAXI GRB220607.31: Global MASTER-Net observations report
- MAXI GRB220607.41: Global MASTER-Net observations report
- GRB 220606A: Swift/BAT-GUANO detection
- GRB 220527A: A BdHN I with a clear UPE phase
- 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
- IPN triangulation of GRB 220528A (short)
- GRB 220528A: Fermi GBM Observation
- GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220528A: Fermi GBM Final Localization
- GRB 220527A: REM optical/NIR observations
- 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-XRT afterglow detection
- Swift trigger 1108208 is not an interesting astrophysical event.
- GRB 220527A: Fermi GBM Observation
- GRB 220527A: Fermi GBM Final Localization
- GRB 220525A: Fermi GBM Detection
- Fermi GRB 220525A: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-220524A
- IPN triangulation of GRB 220524A
- IceCube-220524A: Upper limits from a search for additional neutrino events in IceCube
- GRB 220525A: BALROG localization (Fermi Trigger 675130259 / GRB 220525008)
- GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
- GRB 220521A: MITSuME Akeno optical upper limits
- 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: RATIR Optical and NIR Observations
- GRB 220521A: Swift-XRT refined Analysis
- GRB 220521A: Swift/UVOT Upper Limits
- GRB 220521A: SAO RAS optical observations
- GRB 220521A: Enhanced Swift-XRT position
- GRB 220521A: NOT optical afterglow detection
- GRB 220521A: Swift detection of a burst
- Swift BAT Trigger 1107209 is not an astrophysical event
- GRB 220518A: Swift-BAT refined analysis
- GRB 220518A: Swift-XRT refined Analysis
- Continued Chandra monitoring of GW170817 at ~4.8 yr post-merger
- GRB 220518A: Swift/UVOT Detection
- GRB 220518A: Enhanced Swift-XRT position
- GRB 220518A: Swift detection of a burst
- GRB 220514A: MITSuME Akeno optical observation
- GRB 220514A: GRANDMA Optical Afterglow Observations
- Konus-Wind detection of GRB 220506A
- Konus-Wind detection of GRB 220514B
- GRB 220514A: Fermi GBM observation
- GRB 220514B: Swift-XRT observations
- GRB 220511A: Swift-XRT afterglow detection
- Fermi-LAT Gamma-ray Observations of IceCube-220513A
- IceCube-220513A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-220513A: No significant detection in HAWC
- GRB 220514B: MAXI/GSC detection
- MAXI GRB220514.98: Global MASTER-Net observations report
- GRB 220514A: MeerLICHT optical afterglow candidate