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.
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"25905 results found.
- GRB 230123A: Enhanced Swift-XRT position
- GRB 230123A: Zadko observatory - Gingin optical observations
- GRB 230116C: Swift-XRT observations
- GRB 230123A: Swift detection of a burst
- Trigger 1150107: Swift detection of LS V +44 17
- GRB 230116D: 3.6m DOT optical upper limit
- GRB 230116D: Swift-BAT refined analysis
- GRB 230116C: Swift-BAT refined analysis
- GRB 230116D: SAO RAS further observations
- GRB 230116D: SAO RAS photometry
- GRB 230116D: KGO RC-25 optical observations
- GRB 230116D: Sintez-Newton/CrAO optical observations
- GRB 230116D: LCOGT Optical Upper Limit
- GRB 230116D: SAO RAS redshift
- GRB 230116D: Swift-XRT refined Analysis
- GRB 230116D: GIT optical follow-up
- GRB 230116D: Enhanced Swift-XRT position
- GRB 230116D: SAO RAS observations of OT brightening
- GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
- GRB 230116D: Nanshan/NEXT optical afterglow detection
- GRB 230116D: Swift detection of a burst
- Swift GRB230116.88: Global MASTER-Net observations report
- GRB 230116C: Swift detection of a burst
- Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
- GRB 230102A: Fermi GBM Observation
- GRB 221231A: 3.6m DOT optical upper limit
- GRB 230102A: Swift/BAT-GUANO detection outside the coded FOV
- GRB 221231A: Fermi GBM Observation
- GRB 221231A: Swift-XRT afterglow detection
- GRB 221231A: AKO Upper Limit
- GRB 221231A: Swift-XRT observations
- GRB 221231A: Swift ToO observations
- GRB 221231A: Swift/BAT-GUANO arcminute localization of a possibly short burst
- GRB 221226A: Fermi GBM detection
- IPN triangulation of GRB 221226A
- GRB 221226A: Swift/BAT-GUANO detection outside the coded FOV
- ZTF22acaruqr/AT2022adzb: Neil Gehrels Swift Observatory X-ray detection
- GRB 221226B: LCOGT Optical Upper Limits
- GRB 221226B Swift-BAT refined analysis
- GRB 221226B: Swift-UVOT Detection
- GRB 221226B: Fermi GBM Observation
- GRB 221226B: Swift-XRT refined Analysis
- GRB 221226B: VLT/X-shooter redshift and host galaxy
- GRB 221226B: Enhanced Swift-XRT position
- GRB 221226B: Swift detection of a burst
- Swift GRB221226.95: Global MASTER-Net observations report
- GRB 221218A: 3.6m DOT optical upper limit
- GRB 221218A: BOOTES-4/MET and OSN optical upper limits
- GRB 221218A: KAIT Optical Upper Limit
- GRB 221215A: Fermi GBM Detection
- GRB 221216A: Swift/UVOT Upper Limits
- GRB 221216A: Fermi GBM observation
- GRB 221216A: Swift-XRT refined Analysis
- GRB 221216A: AKO Upper Limit
- GRB 221215A: Swift-XRT observations
- GRB 221216A: Enhanced Swift-XRT position
- Swift GRB 221216A: Global MASTER-Net observations report
- GRB 221216A: Zadko observatory - Gingin optical observations
- GRB 221216A: Nanshan/NEXT optical upper limits
- GRB 221216A: Swift detection of a burst
- GRB 221215A: Swift ToO observations
- GRB 221215A: Swift/BAT-GUANO arcminute localization
- Swift GRB221215.15: Global MASTER-Net observations report
- Swift Trigger 1144538 is not a GRB
- GRB 221009A: MuSCAT3 observations
- GRB 221206B: Fermi GBM observation
- GRB 221206B: Swift-XRT observations
- GRB 221206B: Detection by GRBAlpha
- GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
- GRB 221206B: Swift ToO observations
- Swift/BAT trigger #1143281 is not a GRB
- Swift GRB221204.45 AKO Upper Limit
- Swift GRB221204.45: Global MASTER-Net observations report
- GRB 221202A: Swift/UVOT Detection
- GRB 221202A: Swift-BAT refined analysis
- GRB 221202A: VLT/FORS2 Afterglow Discovery
- GRB 221201A: Swift-BAT refined analysis
- GRB 221201A: Fermi GBM observation
- GRB 221202A: Swift-XRT refined Analysis
- GRB 221202A: LCOGT Optical Upper Limits
- GRB 221202A: Enhanced Swift-XRT position
- GRB 221202A: MeerLICHT upper limits
- GRB 221202A: Swift detection of a burst
- Swift GRB221202.84: Global MASTER-Net observations report
- GCN: GRB 221201A: Swift/UVOT Upper Limits
- GRB 221201A: Swift-XRT refined Analysis
- GRB 221201A: Enhanced Swift-XRT position
- Swift GRB 221201A: Global MASTER-Net observations report
- Konus-Wind detection of GRB 221124A
- GRB 221201A: Swift detection of a burst
- GRB 221126A: Fermi GBM observation
- GRB 221126A: AGILE detection
- GRB 221126A: AstroSat CZTI detection
- GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
- IPN triangulation of GRB 221124A (long)
- GRB 221124A: Swift/BAT-GUANO detection
- GRB 221120A: Detection by VZLUSAT-2
- GRB 221120A: TURBO Optical Upper Limit
- GRB 221120A: VIRT Optical Upper Limit
- GRB 221009A：DAMPE observed a 34.7 GeV photon at 1.36 hour after the GBM trigger