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 161129A: MITSuME Okayama Optical Observation
- GRB 161129A: Swift/UVOT Detection
- GRB 161129A: Tautenburg Ic-band observations
- GRB 161129A: TSHAO optical observations / possible afterglow+host galaxy
- GRB161129A : Astrosat CZTI detection
- GRB 161129A: Swift-XRT refined Analysis
- GRB 161129A: Enhanced Swift-XRT position
- GRB 161129A: Swift detection of a burst
- Fermi GBM trigger 501785179/161125699 is not a GRB
- Fermi GBM trigger 501779084/161125628 is not a GRB
- GRB 161123A: Swift-XRT observations
- Swift Trigger 723539 is not an astrophysical event
- GRB 161123A: Tiled Swift observations
- GRB 161123A: MAXI/GSC detection
- GRB 161117A: SMARTS optical/IR afterglow observations
- GRB 161119A: MASTER-SAAO possible OT detection during Fermi Alert
- GRB 161108A: 15 GHz upper limits from AMI
- Swift Trigger 723124 is probably not a GRB
- GRB 161117B: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 161117A
- GRB 161117A iTelescope observation
- GRB 161117A: MASTER-OAFA (Argentina) prompt OT observations
- GRB 161117A: TAROT La Silla observatory optical observations
- GRB 161117A: GMG observation limit
- GRB 161117A: Fermi GBM detection/observation
- GRB 161117B: Swift/UVOT Upper Limits
- GRB 161117A: Swift/UVOT Detection
- GRB 161117B: Swift-BAT refined analysis
- GRB 161117A: Swift-BAT refined analysis
- Swift Trigger 722681 is probably not a GRB
- GRB 161117B: Enhanced Swift-XRT position
- GRB 161117A: Swift-XRT refined Analysis
- GRB 161117A: Enhanced Swift-XRT position
- GRB 161117B: LCO optical observations
- GRB 161117B: Swift detection of a burst
- GRB161117A: REM optical and NIR afterglow detection
- GRB 161117A: VLT/X-shooter spectroscopy and redshift
- GRB 161117A: Swift detection of a burst with an optical counterpart
- GRB 161113A: Swift-BAT refined analysis
- GRB 161113A: Swift/UVOT Upper Limits
- GRB 161113A: Swift-XRT refined Analysis
- GRB 161113A: Kuban State University optical upper limit
- GRB 161113A: Enhanced Swift-XRT position
- GRB 161113A: RATIR Optical and NIR Observations
- GRB 161113A: Swift detection of a burst
- GRB 161109A: CALET Gamma-Ray Burst Monitor detection
- GRB 161109A: Swift/UVOT Upper Limits
- GRB 161104A: Magellan imaging and spectroscopy
- GRB 161108A: continued TSHAO optical observations
- GRB 161104A: Chandra X-ray observations
- GRB 161109A: Lomonosov BDRG gamma ray discovery
- GRB 161109A: Swift-XRT observations
- GRB 161108A: MITSuME Okayama upper limits
- IceCube-161103: CALET Gamma-Ray Burst Monitor upper limits
- GRB 161106A: CALET Gamma-Ray Burst Monitor detection
- GRB 161108A: TSHAO optical observations
- GRB 161108A: Swift/UVOT Upper Limits
- GRB 161109A: Tiled Swift observations
- GRB 161105A: Swift/UVOT Upper Limits
- GRB 161109A: Fermi GBM observation
- GRB 161109A: Fermi-LAT detection
- GRB 161106A: Lomonosov BDRG gamma ray discovery
- GRB 161108A: TAROT Calern observatory optical observations
- GRB 161105A: TAROT La Silla observatory optical observations
- GRB 161108A, Swift-BAT refined analysis
- GRB 161108A: NOT redshift
- GRB 161108A: RATIR Afterglow Confirmation
- GRB 161108A: Swift-XRT refined Analysis
- GRB 161108A: Enhanced Swift-XRT position
- GRB 161108A: NOT candidate afterglow
- GRB 161108A: Swift detection of a burst
- Fermi LAT Gamma-ray Observations of IceCube-161103
- GRB 161022A: 15 GHz upper limits from AMI
- GRB 161017A: 15 GHz upper limits from AMI
- GRB 161103A: an ultra-long GRB detected by Konus-Wind
- GRB 161106A: Fermi GBM detection
- IceCube-161103: Konus-Wind upper limits
- GRB 161105A: Swift-XRT refined Analysis
- GRB 161104A: Gemini South optical observations
- GRB 161105A: Swift-BAT refined analysis
- GRB 161105A: Enhanced Swift-XRT position
- Search for counterpart to IceCube-161103A with ANTARES
- GRB 161105A: MASTER-IAC early optical observations
- GRB 161104A: GROND observations
- GRB 161105A: Swift detection of a burst
- GRB 161104A: Swift/UVOT Upper Limits
- GRB 161104A, Swift-BAT refined analysis
- GRB 161104A: Swift-XRT refined Analysis
- Fermi GBM Observations of IceCube-161103
- GRB 160928A: The first GRB detected by POLAR
- IceCube-161103: Swift-XRT observations
- GRB 161104A: Enhanced Swift-XRT position
- GRB 161104A: Swift detection of a short burst
- INTEGRAL SPI-ACS and IBIS/Veto observation of IceCube-161103
- IceCube-161103: MASTER follow-up observations
- HAWC follow up of IceCube-161103
- IceCube-161103: IceCube observation of a very-high-energy neutrino
- GRB 161020A: Fermi GBM observation
- Fermi GBM trigger 499467682/161029876 is not a GRB
- GRB 161015A: 15 GHz upper limits from AMI