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"- GRB 220701A: BOOTES-5/JGT early optical upper limit
- GRB 220701A: Swift/UVOT Upper Limits
- GRB 220701A: Lowell Discovery Telescope Optical Observations
- GRB 220701A: Enhanced Swift-XRT position
- GRB 200701A: KAIT Optical Upper Limit
- GRB 220701A: Swift detection of a burst
- Fermi-LAT Gamma-ray Observations of IceCube-220629A
- GRB 220627A, GROND observations
- GRB 220624A: AGILE/GRID refined analysis
- GRB 220627A: Swift/UVOT Upper Limits
- Fermi-LAT Gamma-ray Observations of IceCube-220627A
- IceCube-220629A: No significant detection in HAWC
- IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
- IceCube-220627A: No significant detection in HAWC
- IceCube Alert 220629.99: Global MASTER-Net observations report
- GRB 220627A: Swift-XRT afterglow detection
- Konus-Wind detection of GRB 220627A
- Trigger 1113743: Swift detection of MAXI J0655-013
- IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
- IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
- GRB 220627A: VLT MUSE redshift
- Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
- GRB 220627A: MeerLICHT candidate optical afterglow
- GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
- GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
- Konus-Wind detection of GRB 220624A
- Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
- GRB 220627A: Swift ToO observations
- GRB 220627A: Fermi-LAT detection
- Fermi trigger No 678058621: Global MASTER-Net observations report
- GRB 220627A: MeerLICHT detection of two afterglow candidates
- Fermi GRB 220627A: Global MASTER-Net observations report
- IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
- GRB 220627A: Fermi GBM Final Real-time Localization
- IceCube-220627A - IceCube observation of a high-energy neutrino candidate track-like event
- IceCube Alert 220627.74: Global MASTER-Net observations report
- IceCube-220624A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-220624A: No significant detection in HAWC
- GRB 220623A: GIT optical upper limits.
- GRB 220624A: CALET Gamma-Ray Burst Monitor detection
- GRB 220623A: T193-OHP optical upper limit
- IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
- GRB 220624A: Fermi GBM Detection
- Fermi GRB 220623B: Global MASTER-Net observations report
- Fermi GRB 220624A: Global MASTER-Net observations report
- IceCube Alert 220624.68: 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 220611A: X-ray afterglow Chandra sub-arcsecond localization
- GRB 220624A: AGILE/GRID analysis
- IceCube-220624A - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 220624A: AGILE detection
- Konus-Wind detection of GRB 220623A
- GRB 220624B: Fermi GBM Final Real-time Localization
- GRB 220624A: Fermi GBM Final Real-time Localization
- 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
- Konus-Wind detection of GRB 220609B
- GRB 220623B: Fermi GBM Final Real-time Localization
- GRB 220623A: Enhanced Swift-XRT position
- GRB 220623A: AGILE detection
- GRB 220623A: AstroSat CZTI detection
- GRB 220623A: iTelescope optical upper limit
- GRB 220623A: Swift-XRT observations
- GRB 220623A: Swift detection of a burst
- Fermi trigger No 677597318: Global MASTER-Net observations report
- GRB 220618A: Fermi GBM detection
- Swift Detection of MAXI J0655-013
- GRB 220618A: Swift-BAT refined analysis
- GRB 220618A: iTelescope T-19 upper limit
- Konus-Wind detection of GRB 220617A
- Fermi trigger No 677377371: Global MASTER-Net observations report
- Fermi GRB 220620B: Global MASTER-Net observations report
- Fermi GRB 220620A: Global MASTER-Net observations report
- GRB 220620B: Fermi GBM Final Real-time Localization
- Integral GRB220619.53: Global MASTER-Net observations report
- GRB 220619A: AstroSat CZTI detection
- Swift GRB220620.02: Global MASTER-Net observations report
- GRB 220620A: Fermi GBM Final Real-time Localization
- GRB 220611A: Continued Gemini Infrared Observations
- GRB 220617A: TNG optical observations
- Fermi trigger No 677307509: Global MASTER-Net observations report
- Fermi trigger No 677236224: Global MASTER-Net observations report
- GRB 220617A: Fermi GBM observation
- Swift Trigger 1110865 is probably not an astrophysical event
- GRB 220611A optical counterpart
- GRB 220618A: Swift-XRT refined Analysis
- IPN triangulation of GRB 220617A (short)
- GRB 220618A: BOOTES-5/JGT early optical upper limit
- 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
- Swift GRB220618.38: Global MASTER-Net observations report
- GRB 220617A: Fermi-LAT detection