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"31730 results found.
- GRB 200701A: KAIT Optical Upper Limit
- 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
- GRB 220627A: Swift-XRT afterglow detection
- Konus-Wind detection of GRB 220627A
- IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
- 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
- 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
- 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
- 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
- GRB 220624A: AGILE detection
- Konus-Wind detection of GRB 220623A
- GRB 220623A: AbAO optical upper limit
- GRB 220623A: Swift-XRT refined Analysis
- GRB 220623A: NOT optical observations
- GRB 220623A: Swift/UVOT Upper Limits
- Konus-Wind detection of GRB 220609B
- GRB 220623A: AGILE detection
- GRB 220623A: AstroSat CZTI detection
- GRB 220623A: iTelescope optical upper limit
- 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 GRB 220620B: Global MASTER-Net observations report
- Fermi GRB 220620A: Global MASTER-Net observations report
- GRB 220611A: Continued Gemini Infrared Observations
- GRB 220617A: TNG optical observations
- GRB 220617A: Fermi GBM observation
- GRB 220611A optical counterpart
- GRB 220618A: Swift-XRT refined Analysis
- IPN triangulation of GRB 220617A (short)
- GRB 220618A: Swift/UVOT Upper Limits
- GRB220611A: Gemini Optical Afterglow Confirmation
- GRB 220617A: Swift-XRT observations
- GRB 220617A: Fermi-LAT detection
- GRB 220617B: Swift ToO observations
- Fermi GRB 220617A: Global MASTER-Net observations report
- GRB 220611A: Gemini Ks counterpart detection
- Konus-Wind detection of GRB 220613A
- IPN triangulation of GRB 220613A
- GRB 220611A: Gemini South Infrared Detection
- IPN triangulation of GRB 220606C
- GRB 220611A: Swift/UVOT Upper Limits
- GRB 220612A: CALET Gamma-Ray Burst Monitor detection
- GRB 220611A: Swift-BAT refined analysis
- Swift GRB 220611A: Global MASTER-Net observations report
- GRB 220611A: Swift-XRT refined Analysis
- IPN triangulation of GRB 220609B
- Fermi GRB 220610A: Global MASTER-Net observations report
- GRB 220609B: AstroSat CZTI detection
- GRB 220608A: AstroSat CZTI detection
- GRB 220606A: Fermi GBM observation
- Fermi GRB 220608A: Global MASTER-Net observations report
- GRB 220606B: Gemini South Optical Observations
- GRB 220606B: Fermi GBM Observation
- GRB 220606B: Swift follow-up observations
- Konus-Wind detection of GRB 220601A
- 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
- Fermi GRB 220606B: Global MASTER-Net observations report
- IPN triangulation of GRB 220601A (long)
- Fermi-GBM will trial new SAA regions from Tuesday June 7th
- 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
- Fermi GRB 220530A: Global MASTER-Net observations report