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"34124 results found.
- GRB 220210A: Fermi-LAT detection
- GRB 220210A: AGILE detection
- GRB 220210A: BOOTES-5/JGT optical afterglow candidate discarded
- GRB 220210A: BOOTES-5/JGT optical afterglow candidate
- GRB 220210A: Swift/BAT-GUANO localization
- Fermi GRB 220211A: Global MASTER-Net observations report
- GRB 220211A: Fermi GBM Final Real-time Localization
- Fermi GRB 220210A: Global MASTER-Net observations report
- GRB 220210A: Fermi GBM Final Real-time Localization
- GRB 210919A: Maidanak optical observations
- GRB 210919A: SPI-ACS/INTEGRAL observation and evaluation of Ep
- GRB 220209A: Fermi GBM Detection
- GRB 220209A: GECAM detection
- GRB 220209A: AGILE/MCAL detection
- Fermi GRB 220209A: Global MASTER-Net observations report
- GRB 220209A: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 220130A
- Konus-Wind detection of GRB 220203A
- GRB 220203A: GECAM detection
- GRB 220203A: Swift/BAT-GUANO detection outside the coded FOV
- IPN triangulation of GRB 220203A (short)
- IPN triangulation of GRB 220130A
- Swift Reaction Wheel Anomaly Update (4 Feb 2022)
- GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
- GRB 220131B: Swift/BAT-GUANO detection outside the coded FOV
- GRB 220201A: Fermi GBM Final Localization
- GRB 220128A: AstroSat CZTI detection
- GRB 220130A: Fermi GBM Observation
- Konus-Wind detection of GRB 220128A
- IPN triangulation of GRB 220128A (long)
- Fermi GRB 220131A: Global MASTER-Net observations report
- GRB 220131B: GECAM detection
- GRB 220130A: GECAM detection
- GRB 220131A: Fermi GBM Final Real-time Localization
- Fermi GRB 220129A: Global MASTER-Net observations report
- GRB 220129A: Fermi GBM Final Real-time Localization
- GRB 220127A: GECAM detection
- Konus-Wind detection of GRB 220124A
- IPN triangulation of GRB 220124A
- GRB 220124A: GECAM detection
- GRB 220117A, GROND observations
- GRB 220124A: AstroSat CZTI detection of a bright long GRB
- GRB 220117A: Terskol and AbAO optical upper limits
- GRB 220118A: TARGET optical upper limit
- GRB 220117B: TARGET optical upper limit
- GRB 220121B: GECAM detection
- IPN triangulation of a bright burst from SGR 1935+2154
- GRB 220117A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
- IPN triangulation of GRB 211226A
- GRB 220120A: Fermi GBM Final Localization
- GRB 220117C: Fermi GBM Observation
- GRB 220118A: 2.2m CAHA/CAFOS detections
- GRB 220118A: Fermi GBM detection
- GRB 220118A: COATLI Optical Observations
- GRB 220101A: KAO optical-R observation
- GRB 211221A: No V & R detection, KAO telescope
- GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
- GRB 220117C: Swift/BAT-GUANO arcminute localization
- GRB 220118A: Swift-BAT refined analysis
- GRB 220118A: Swift/UVOT Detection
- GRB 220118A: GIT optical observations
- GRB 220118A: Enhanced Swift-XRT position
- GRB 220118A: MITSuME Akeno optical observation
- GRB 220117B: z-band limit
- Swift GRB 220118A: Global MASTER-Net observations report
- GRB 220118A: Swift detection of a burst with an optical counterpart
- GRB 220118A: Fermi GBM Final Real-time Localization
- GRB 220117A: MITSuME Akeno optical upper limits
- Fermi GBM Sub-Threshold Detection of GRB 220117A
- GRB 220117B: Swift-BAT refined analysis
- GRB 220117A: Swift-BAT refined analysis
- GRB 220117B: Swift/UVOT Upper Limits
- GRB 220117A: Swift/UVOT Upper Limits
- GRB 220117A: LCO Optical Observations
- GRB 220117A: VLT/X-shooter optical afterglow and redshift
- GRB 220117B: Swift-XRT refined Analysis
- GRB 220117A: Swift-XRT refined Analysis
- GRB 220117B: Nanshan/NEXT optical upper limit
- GRB 220117B: MITSuME Akeno optical upper limits
- GRB 220117B: Enhanced Swift-XRT position
- GRB 220117A: Enhanced Swift-XRT position
- GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
- Swift GRB 220117A: Global MASTER-Net observations report
- Swift GRB 220117B: Global MASTER-Net observations report
- GRB 220117B: Swift detection of a burst
- GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
- GRB 220117A: Swift detection of a burst
- GRB 220101A: The most powerful GRB and BDHN I in 26 years
- GRB 220115B: Fermi GBM Final Real-time Localization
- GRB 210919A: LBT spectroscopic redshift of the host galaxy candidates
- GRB 220115A: Fermi GBM Final Real-time Localization
- Fermi Gamma-ray Burst Monitor trigger 663917434/220115230 is not a GRB
- GRB 220114A: Fermi GBM Final Localization
- Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
- GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
- GRB 220111A: AstroSat CZTI detection
- Fermi GRB 220111A: Global MASTER-Net observations report
- Konus-Wind detection of GRB 220101A (correction to GCN 31433)
- GRB 220111A: BALROG localization (Fermi Trigger 663621714 / GRB 220111807)
- GRB 220111A: Fermi GBM Final Real-time Localization