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 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
- GRB 161014A: 15 GHz upper limits from AMI
- GRB161023A: AstroSat CZTI detection
- GRB 161023A: GROND Observations
- GRB 161023A: Swift-XRT afterglow detection
- Konus-Wind observation of GRB 161023A
- GRB 161023A: TAROT La Silla observatory optical observations
- GRB 161023A: Zadko observatory - Gingin optical observations
- GRB 161023A: Watcher optical observations
- GRB 161023A: LCOGT-FTS optical observations
- GRB 161023A: Swift ToO observations
- Radio upper limit on the GRB 161011A with the GMRT
- GRB 161023A VLT/X-shooter redshift
- GRB 161023A: A long GRB detected by INTEGRAL
- GRB 161023A (Integral trigger 7613) MASTER-Net bright OT detection
- Swift Trigger 718919 is not an astrophysical event.
- GRB 161022A: Swift-BAT refined analysis
- Swift Trigger 718766 is not an astrophysical event.
- GRB 161022A: RATIR Optical and NIR Observations
- GRB 161022A: Swift/UVOT Upper Limits
- GRB 161022A: Fermi GBM observation
- GRB 161022A: NOT optical observations
- GRB 161022A: Enhanced Swift-XRT position
- Konus-Wind observation of GRB 161020B
- GRB 161022A: Swift-XRT refined Analysis
- IPN Triangulation of GRB 161020B
- GRB 161022A: LT observations
- GRB 161022A: TAROT Calern observatory optical observations
- GRB 161022A: Prompt enhanced Swift-XRT position
- GRB 161022A: Swift detection of a burst
- GRB 161020A: A long GRB detected by INTEGRAL
- GRB 161015A: further Swift-XRT follow-up observations
- GRB 161011A: 15 GHz upper limits from AMI
- GRB 161007A: 15 GHz upper limits from AMI
- Konus-Wind observation of GRB 161017A
- GRB161017A: NOEMA detection of the millimetre afterglow
- GRB 161017A: LT optical observations
- GRB161017A optical R band observations with SARA-RM
- GRB 161017A: TNG spectroscopy and redshift confirmation
- GRB 161017A: GTC additional spectroscopy and refined redshift
- GRB 161017A: Swift-BAT refined analysis
- GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
- GRB 161017A: Swift/UVOT Detection
- GRB 161017A: Swift-XRT refined Analysis
- GRB161017A: optical observations with 1-m LCOGT McDonald
- GRB 161017A: TNG optical observations
- GRB 161017A: MITSuME Akeno Optical Observation
- GRB 161017A: Redshift from GTC
- GRB 161017A: Fermi GBM observation
- GRB 161017A: Enhanced Swift-XRT position
- GRB 161014A: Continued RATIR Optical and NIR Observations
- GRB 161015A: Swift/UVOT observations
- GRB 161017A: Swift detection of a burst with a bright optical afterglow
- GRB161017.74 MASTER-Net OT detection
- Konus-Wind observation of GRB 161015A
- GRB 161014A: VLT/X-shooter redshift confirmation
- GRB161015A: AstroSat CZTI detection
- Konus-Wind observation of GRB 161014A
- GRB 161014A: refined analysis of TSHAO optical observations
- GRB 161015A: Swift-XRT observations
- GRB 161015A: Fermi GBM detection
- GRB 161015A: Tiled Swift observations
- GRB 161015A: Fermi-LAT detection
- GRB161004A: Further analysis of the burst nature
- GRB 161014A: RATIR Optical and NIR Observations
- GRB 161014A: Fermi GBM observation
- GRB 161014A: Swift-XRT refined Analysis
- GRB 161014A: Swift-BAT refined analysis
- GRB 161014A: TNG optical observations
- GRB 161014A: AROMA-N Optical Observation
- GRB 161014A: Continued MITSuME Akeno Optical Observation
- GRB 161014A: Swift/UVOT Detection
- GRB161014A: NOT optical observations
- GRB 161014A: GTC spectroscopy
- GRB 161014A: TSHAO optical observations