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"19668 results found.
- GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
- GRB 231110A: Terskol Zeiss-2000 optical upper limit
- GRB 231111A: Swift-XRT refined Analysis
- GRB 231111A: Mondy optical observations
- GRB 231111A: GECAM-C detection of a long burst (correction)
- GRB 231110A: GECAM-B detection (correction)
- GRB 231111A: Enhanced Swift-XRT position
- GRB 231111A: GECAM-C detection of a long burst
- GRB 231110A: GECAM detection
- GRB 231110A: SAO RAS optical observations
- GRB 231110A: Swift-XRT afterglow detection
- GRB231111A: YAHPT Observations
- GRB231111A: GIT confirmation of the optical afterglow
- GRB 231111A: MASTER OT earlier detection
- GRB 231111A: Nanshan/HMT optical observations
- GRB 231111A: Swift detection of a burst with an optical counterpart
- Swift GRB231111.60: Global MASTER-Net observations report
- GRB231110A: WFST Observation and upper limits
- Swift GRB231110.89: Global MASTER-Net observations report
- GRB 231110A: Swift detection of a burst
- GRB 231104A: Swift-BAT refined analysis
- GRB 231104A: FRAM-ORM optical limit
- LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
- GRB 231104A: NuSTAR Observation of the prompt emission
- GRB 231104A: 3.6m DOT optical upper limit
- GRB 231104A: NOT upper limit
- GRB 231104A: Fermi GBM Observation
- GRB 231104A: AKO Upper Limit
- GRB 231104A: AstroSat CZTI detection
- GRB 231104A: Swift-XRT refined Analysis
- GRB 231104A: Fermi-LAT detection
- GRB 231104A: Swift/UVOT Upper Limits
- GRB 231104A: Enhanced Swift-XRT position
- GRB231104A: LCOGT Optical Upper Limits
- GRB 231104A: Swift detection of a bright burst
- Swift GRB231104.07: Global MASTER-Net observations report
- New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
- IPN triangulation of GRB 231020A
- GRB 231028A: Swift-BAT refined analysis
- LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
- GRB 231028A: CALET Gamma-Ray Burst Monitor detection
- GRB 231028A: AstroSat CZTI detection
- GRB 231028A: Glowbug gamma-ray detection
- GRB 231028A: Fermi GBM Detection
- Swift GRB 231028A: Global MASTER-Net observations report
- GRB 231028A: Swift detection of a burst
- GRB 231025A: Fermi GBM Observation
- GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
- GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
- LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
- GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
- GRB 231017A: 1.3m DFOT Optical upper limit
- GRB 231018A: Glowbug gamma-ray detection
- IPN triangulation of GRB 231018A
- GRB 231017A: Swift/UVOT Upper Limit
- GRB 230911C: ATCA detection of possible radio counterpart
- GRB 231017A: GOTO optical upper limits
- GRB 231017A: JinShan optical upper limit
- GRB 231017A: Las Cumbres optical upper limit
- GRB 231017A: LCOGT Optical Upper Limits
- GRB231017A: GROWTH-India upper limits on the optical afterglow
- GRB 231017A: Fermi GBM Detection
- GRB 231017A: Swift-XRT observations
- GRB 231017A: Swift ToO observations
- GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
- LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
- NuEm-230927A: Swift-XRT follow-up
- Swift Triggers 1192745 and 1192747 are not astrophysical events
- Swift Triggers 1192740, 1192742 and 1192743 are not astrophysical events
- Swift Triggers 1192735 and 1192737 are not astrophysical events
- Konus-Wind detection of GRB 230919A
- LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
- LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
- IPN triangulation of GRB 230919A (short)
- GRB 230919A: Fermi GBM Observation
- GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
- LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
- GRB 230915A: Fermi GBM observation
- Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
- GRB 230911A: Fermi GBM Observation
- Swift GRB230916.18: Global MASTER-Net observations report
- GRB 230915A: Swift/BAT-GUANO detection of a burst
- LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
- Swift GRB230916.19: Global MASTER-Net observations report
- Swift GRB230916.18: Global MASTER-Net observations report
- Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
- Swift GRB230916.13: Global MASTER-Net observations report
- Swift GRB230916.12: Global MASTER-Net observations report
- Swift GRB230916.11: Global MASTER-Net observations report
- Swift Trigger 1192233 is not a GRB
- GRB 230911A: Swift-XRT afterglow detection
- GRB 230913A: CALET Gamma-Ray Burst Monitor detection
- Swift Trigger 1192088 is not an astrophysical event