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.
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"
6097 results found.
- GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
- GRB 210928A: Swift-XRT refined Analysis
- GRB 210928A: Fermi GBM observation
- GRB 210928A: Fermi-LAT detection
- GRB 210930A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCubeCascade-210926A
- IceCube-210922A: No significant detection in HAWC
- IceCube-210922A: No neutrino counterpart candidates in ANTARES search
- Fermi-LAT Gamma-ray Observations of IceCube-210922A
- GRB 210919A: Swift-XRT refined Analysis
- GRB 210912A: Swift-XRT refined Analysis
- GRB 210826A: further Swift-XRT observations
- GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
- Konus-Wind detection of GRB 210905A
- GRB 210905A: Swift-XRT refined Analysis
- GRB 210610A: Maidanak and AbAO optical observations
- Swift GRB 210905A: Global MASTER-Net observations report
- Swift GRB210903.58: Global MASTER-Net observations report
- GRB 210901A: Swift-XRT refined Analysis
- GRB 210827A: further Swift-XRT observations
- GRB 210827A: Swift-XRT observations
- GRB 210826A: Swift-XRT observations
- GRB 210826A: Fermi-LAT detection
- GRB 210824A: Swift-XRT refined Analysis
- Konus-Wind detection of GRB 210822A
- GRB 210822A: Swift-XRT refined Analysis
- GRB 210822A: Fermi-LAT detection
- GRB 210820A: Swift-XRT refined Analysis
- GRB 210818A: Swift-XRT refined Analysis
- GRB 210712A: Fermi GBM observation
- Fermi-LAT Gamma-ray Observations of IceCube-210811A
- GRB 210802A: Further Swift/XRT observation and afterglow confirmation
- GRB 210807C: Swift-XRT refined Analysis
- GRB 210807C: Fermi GBM detection
- GRB 210807A: Swift-XRT refined Analysis
- GRB 210803A: Fermi GBM observation
- GRB 210802A: Swift-XRT afterglow detection
- GRB 210802A: Fermi GBM detection
- GRB 210802A: Fermi-LAT detection
- GRB 210801A: Fermi GBM detection
- IceCube-210730A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- GRB 210731A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-210730A
- GRB 210726A: Chandra detection of the X-ray afterglow
- GRB 210730A: Fermi GBM observation
- GRB 210730A: Swift-XRT refined Analysis
- GRB 210714A: Fermi GBM observation
- GRB 210726A: Swift-XRT refined Analysis
- GRB 210725B: Swift-XRT refined Analysis
- GRB 210725A: Fermi GBM detection
- GRB 210725A: Swift-XRT refined Analysis
- GRB 210724A: Swift-XRT refined Analysis
- GRB 210723A: Swift-XRT refined Analysis
- GRB 210722A: Fermi GBM observation
- GRB 210722A: Swift-XRT refined Analysis
- Fermi-LAT Gamma-ray Observations of IceCube-210717A
- IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- GRB 210704A: Zeiss-1000/SAO-RAS optical observations
- Fermi trigger No 647942198: Global MASTER-Net observations report
- GRB 210712A: Swift-XRT refined Analysis
- GRB 210706A: Swift/XRT afterglow confirmation
- GRB 210708A: Swift-XRT refined Analysis
- Fermi GBM Observations of SGR J1935+2154
- GRB 210706A: Fermi GBM observation
- GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO
- GRB 210704A: OAJ T80 multi-color detections
- GRB 210706A: Swift-XRT afterglow detection
- Integral GRB210707.02: Global MASTER-Net observations report
- GRB 210704A: CAHA 2.2m Afterglow Detection
- GRB 210704B: Fermi GBM detection
- GRB 210704A: Fermi GBM detection
- GRB 210704A: Swift-XRT afterglow detection
- IceCube-210516A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- IceCube-210510A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- GRB 210704A: Fermi-LAT detection
- GRB 210705A: AGILE/MCAL detection of a burst
- Konus-Wind detection of GRB 210702A
- GRB 210702A: iTelescope optical afterglow observations
- GRB 210702A: Swift-XRT refined Analysis
- IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- Fermi-LAT Gamma-ray Observations of IceCube-210629A
- GRB 210626A: Swift/XRT afterglow confirmation
- GRB 210626A: Fermi GBM observation
- GRB 210626A: GIT optical upper limit
- GRB 210626A: Swift-XRT afterglow detection
- GRB 210622A: Swift-XRT observations
- Fermi GBM observation of a bright burst in the direction of SGR 1935+2154
- GRB 210618A: Swift-XRT afterglow detection
- GRB 210619B: Even further SAO RAS optical observations
- GRB 210622A: Fermi GBM detection
- GRB 210619B: Further SAO RAS optical observations
- GRB 210619B: iTelescope optical afterglow observation
- GRB 210619B: SAO RAS optical observations
- GRB 210619B: GIT optical follow-up and confirmation of jet-break
- GRB 210619B: Fermi GBM detection
- GRB 210619B: Fermi-LAT detection
- GRB 210619B: Swift-XRT refined Analysis
- GRB 210618A: Fermi GBM observation
- GRB 210618A: Swift-XRT observations
- GRB 201008A: Fermi GBM observation