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"28059 results found.
- GRB 181030A: SAO RAS optical observations
- GRB 181030A: Swift detection of a burst with a possible optical counterpart
- GRB 181028A: Fermi GBM observation
- GRB 181027A: Fermi GBM detection
- GRB 181027A: Swift-BAT refined analysis
- IceCube-181023A: HAWC follow-up
- IceCube-181023A: MASTER Net optical alert and follow up observations
- Fermi-LAT Gamma-ray Observations of IceCube-181023A
- GRB 181023A: Swift-BAT refined analysis
- GRB 181023A: Swift/UVOT Upper Limits
- GRB 181022A: Swift-XRT refined Analysis
- GRB 181023A: Swift-XRT refined Analysis
- GRB 181022A: GROND upper limits
- GRB 181022A: LCO Sutherland observations
- GRB 181023A: Enhanced Swift-XRT position
- GRB 181022A: Swift/UVOT Upper Limits
- GRB 181023A: Swift detection of a burst
- GRB 181022A: Swift-BAT refined analysis
- GRB 181022A: Swift detection of a burst
- GRB 181020A: Swift/UVOT Detection
- GRB 181020A: LCO Cerro Tololo observations
- GRB 181020A: Swift-BAT refined analysis
- GRB 181018A: Insight-HXMT/HE detection
- GRB 181017A: Insight-HXMT/HE detection
- GRB 181020A: Swift-XRT refined Analysis
- GRB 181020A: Fermi GBM detection
- GRB 181020A: Enhanced Swift-XRT position
- GRB 181020A: Swift detection of a burst with an optical counterpart
- FRB 181016: MASTER optical inspection of the Fast Radio Burst error box
- GRB 181014A: Insight-HXMT/HE detection
- Fermi GBM Observation of IceCube-181014A
- GRB 181016A: Swift-BAT refined analysis
- GRB 181013A: AbAO optical upper limit
- Search for counterparts to IceCube-181014A with IceCube
- Fermi-LAT Gamma-ray Observations of IceCube-181014A
- GRB 181013A: Swift/UVOT Upper Limits
- GRB 181013A: Swift-BAT refined analysis
- GRB 181013A: Swift-XRT afterglow detection
- GRB 181013A: Swift detection of a probable burst
- GRB 181011A: Global MASTER Net optical inspection
- GRB 181011A: MAXI/GSC detection
- GROND afterglow detection of GRB 181010A
- GRB 181008B: Global MASTER Net optical inspection
- GRB 181010A: Swift-BAT refined analysis
- IPN Triangulation of GRB 181008B (long)
- GRB 181010A: Swift/UVOT Detection
- GRB 181010A: Swift-XRT refined Analysis
- GRB 181008A: Insight-HXMT/HE detection
- GRB 181010A: Enhanced Swift-XRT position
- GRB 181010A: RATIR Optical and NIR Afterglow Detection
- GRB 181010A: LCO Cerro Tololo observations
- GRB 181010A: MASTER-Argentina OT detection
- GRB 181010A: Swift detection of a burst with an optical counterpart
- GRB 181002A: Mondy optical upper limit
- GRB 181003A: RATIR Optical and NIR Observations
- GRB 181003A: Swift-BAT refined analysis
- GRB 181003A: Swift-XRT afterglow detection
- GRB 181003A: Swift/UVOT Upper Limits
- GRB 180930A: TSHAO optical upper limit
- GRB 181002A: Swift-XRT refined Analysis
- GRB 181003A: LCO Cerro Tololo observations
- GRB 181003A: MASTER optical observation
- GRB181002A: GOTO optical limits
- GRB 181002A: Swift/UVOT Upper Limits
- GRB 181003A: Swift-XRT observations
- GRB 181002A: Swift-BAT refined analysis
- GRB 181002A: Enhanced Swift-XRT position
- GRB 181002A: Swift detection of a burst
- GRB 180914B: RTT150 optical observations
- GRB 180914B: RTT150 optical observations
- GRB 180930A: Swift-BAT refined analysis
- GRB 180930A: Swift-XRT refined Analysis
- GRB 180930A: NOT optical upper limits
- GRB 180930A: Swift/UVOT Upper Limits
- GRB 180930A: Enhanced Swift-XRT position
- GRB 180930A: Swift detection of a burst
- GRB 180924A: Swift/UVOT Upper Limits
- GRB 180925A: Insight-HXMT/HE detection
- GRB 180925A: Swift/UVOT Detection
- GRB 180925A: Swift-BAT refined analysis
- GRB 180925A: Swift-XRT refined Analysis
- GRB 180925A: Enhanced Swift-XRT position
- Konus-Wind observation of GRB 180923A
- GRB 180925A: Swift detection of a burst
- GRB 180924A: Swift-XRT refined Analysis
- GRB 180924A: Swift-BAT refined analysis
- GRB 180923B: Fermi GBM detection
- GRB 180924A: Enhanced Swift-XRT position
- GRB 180924A: Swift detection of a burst
- Swift Trigger 863053 is not an astrophysical event
- GRB 180923A: MASTER inspection MAXI/GSC error box
- GRB 180923A: MAXI/GSC detection
- GRB 180914B: DDOTI/OAN Detection and Confirmation of Fading
- GRB 180914B: GOTO optical detection
- GRB 180914B : continued TSHAO optical observations
- GRB 180914B : TSHAO optical observations
- GRB 180914B: Continued RATIR Optical and NIR Observations
- GRB 180914B: Optical counterpart observation from OAJ
- GRB 180914B: RATIR Optical and NIR Observations
- GRB 180914B: Swift-XRT afterglow detection