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"28092 results found.
- GRB 150727A: Swift-XRT refined Analysis
- GRB 150727A: Enhanced Swift-XRT position
- GRB 150724B: Continued RATIR Optical Observations
- GRB 150727A: Swift detection of a burst with an optical counterpart
- GRB 150724B: Swift/UVOT Detection
- GRB 150724B: RATIR Optical Observations
- Swift Trigger 650408 is not a burst
- GRB 150724B: Swift-XRT observations
- IGR J00291+5934, Swift-BAT refined analysis
- GRB 150724B: Fermi GBM detection
- GRB 150724B: Fermi-LAT detection
- GRB 150725A: MAXI/GSC detection
- Trigger 650221: Swift detection of a IGR J00291+5934
- GRB 150724A: Swift-XRT refined Analysis
- Swift IGR J00291+5934: MASTER Optical flare detection
- GRB 150724A: Swift/UVOT Upper Limits
- GRB 150724A: Swift-BAT refined analysis
- GRB 150724A: Enhanced Swift-XRT position
- SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
- GRB 150724A: Swift detection of a burst
- GRB 150722A: LCOGT-Sutherland observations
- GRB 150722A: Swift-BAT refined analysis
- GRB 150722A: Swift-XRT refined Analysis
- GRB 150722A: Swift/UVOT Upper Limits
- GRB 150720A: Swift/UVOT Upper Limits
- GRB 150722A: Enhanced Swift-XRT position
- GRB 150722A: Swift-XRT observations
- GRB 150721A: Fermi GBM detection
- GRB 150720A: Enhanced Swift-XRT position
- GRB 150720A: Swift-XRT refined Analysis
- GRB 150720A: Swift-BAT refined analysis
- Swift Trigger 649706: a possible GRB or bright Galactic transient
- GRB 150711A: Burakan-ISON optical observations
- GRB 150716A: Swift-BAT refined analysis
- GRB 150716A: Swift/UVOT Upper Limits
- GRB 150716A: Continued RATIR Optical Observations
- GRB 150716A: Swift-XRT refined Analysis
- GRB 150716A: RATIR Optical Observations
- GRB 150716A: Swift detection of a burst
- Trigger 649113: Swift detection of SGR 1E 1841-045
- GRB 150710B: Swift-XRT afterglow detection
- GRB 150711A: Swift-BAT refined analysis
- GRB 150710B: Swift-XRT and Swift-UVOT observations
- GRB 150711A: Swift/UVOT Upper Limits
- GRB 150711A: Swift-XRT refined Analysis
- GRB 150711A: Observations from the 2.5m NOT
- GRB 150710B refined analysis
- GRB 150711A: Enhanced Swift-XRT position
- GRB 150711A: Swift detection of a burst
- GRB 150710A: Swift/UVOT Upper Limits
- GRB 150710A: host galaxy for Swift XRT second candidate
- Swift-XRT observations of GRB 150710A
- Konus-Wind observation of GRB 150710A (Swift trigger 648437)
- GRB 150710A: Swift-BAT refined analysis
- GRB 150710A: RATIR Observations
- Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
- Swift Trigger 648422: Swift-XRT observations
- IPN Triangulation of GRB 150702A
- GRB 150702A: MASTER-SAAO inspection
- GRB 150702A: Swift-XRT observations
- GRB 150702A: Fermi-LAT detection
- GRB 150622A: Swift-XRT afterglow detection
- Swift Trigger 647642 is probably not an astrophysical source
- GRB 150626B, Swift-BAT refined analysis
- V404 Cyg activity (Swift, Fermi, INTGRAL, KONUS, MAXI detection): optical observations in TSHAO, Khureltogot, and AAO
- GRB 150627A: Swift/UVOT Detection
- GRB 150627A: Swift-XRT afterglow detection
- GRB 150626B: Swift-XRT refined Analysis
- GRB 150626A: Swift-BAT refined analysis
- GRB 150626B: Swift/UVOT Upper Limits
- GRB 150626B: NOT optical upper limits
- GRB 150626B: Enhanced Swift-XRT position
- GRB 150626B: Swift detection of a burst
- GRB 150626A: Swift-XRT refined Analysis
- GRB 150626A: Swift/UVOT Upper Limits
- GRB 150626A: Enhanced Swift-XRT position
- GRB 150626A: Swift detection of a burst
- Trigger 645944: Swift detection of H1745-203
- V404 Cyg: MASTER Swift, Integral alert observations
- GRB 150622A: Swift-XRT observations
- GRB 150622A: MAXI/GSC detection
- Swift Trigger 645340 was Sco X-1
- Swift Trigger 645340: a possible GRB
- GRB 150616A: Watcher optical upper limit
- Swift triggers again on V404 Cyg
- Swift Trigger 644520 is V404 Cyg
- GRB 150616A: Swift/UVOT Upper Limits
- GRB 150616A: Swift-BAT refined analysis
- V404 Cyg outburst (Swift trigger 643949 ): TSHAO optical observations
- GRB 150616A: Swift-XRT refined Analysis
- Konus-Wind observation of Galactic transient V404 Cyg in outburst
- GRB 150616A: Enhanced Swift-XRT position
- GRB 150616A: Swift detection of a burst
- V404 Cyg: Swift/UVOT Detection
- GRB 150615A, Swift-BAT refined analysis
- Swift trigger 643949 is V404 Cyg
- GRB 150615A: Swift-XRT refined Analysis
- GRB 150608A: Swift-XRT follow-up observations
- GRB 150615A: Swift/UVOT Detection
- GRB 150615A: Enhanced Swift-XRT position