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"20953 results found.
- GRB150819A: NOT imaging
- GRB 150818A: Continued NOT monitoring - afterglow confirmation
- GRB 150818A: Mondy optical observations
- GRB 150819A: RATIR Optical Observations
- GRB 150819A: Swift/UVOT Upper Limits
- GRB150818A: NOT imaging
- GRB 150818A: Swift/UVOT Detection
- GRB 150817A: AAO optical observations
- GRB 150817A: LCOGT observations
- GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
- GRB 150817A: P60 Observations
- MASTER OT inside bright ESO240-010 galaxy detection during FERMI trigger GRB150816.83 inspection
- GRB 150817A: Swift/UVOT Upper Limits
- GRB 150817A: Continued RATIR Observations, Revised Candidate
- GRB 150817A: RATIR Optical Afterglow Candidate
- GRB 150811A: Continued RATIR Observations
- GRB 150811A: Continued RATIR Observations
- GRB 150811A: KAIT Refined Analysis
- GRB 150811A: VLA Detection
- GRB 150811A: Continued RATIR Observations
- GRB 150811A: Swift/UVOT further observations
- GRB 150811A: SAO RAS optical observations
- GRB 150811A: P60 Observations
- GRB 150811A: LCOGT-McDonald afterglow detection
- GRB 150811A: Swift/UVOT Detection
- GRB 150811A: KAIT optical candidate
- GRB 150811A: RATIR Optical Afterglow Detection
- Fermi GBM GRB Trigger 460608875: iPTF P48 Observations
- GRB 150728A: TNG optical observations
- GRB 150727A: IRSF NIR observation
- GRB 150801A: Swift-XRT observations
- GRB 150801B: Swift/UVOT Upper Limits
- Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
- GRB 150721A (Fermi GBM Trigger 459150552): iPTF P48 Observations
- GRB 150801A: Tiled Swift observations
- GRB 150724B: Swift-XRT afterglow detection
- GRB 150424A: HST imaging
- GRB 150728A: Continued RATIR Optical Observations
- GRB 150728A: TSHAO optical observations
- GRB 150728A: RATIR Optical Observations
- GRB 150727A: Continued RATIR Optical Observations - Fading
- GRB 150728A: AAO optical observations
- GRB 150728A: Swift/UVOT Upper Limits
- GRB 150728A: FTN observations
- GRB 150727A: RATIR Optical Observations
- GRB 150727A: Swift-BAT refined analysis
- GRB 150727A: Watcher optical upper limit
- GRB 150727A: Swift/UVOT Detection
- GRB 150727A: LCOGT-Cerro Tololo observations
- GRB 150724B: Continued RATIR Optical Observations
- GRB 150724B: Swift/UVOT Detection
- GRB 150724B: RATIR Optical Observations
- Swift 650221/IGR J00291+5934: Liverpool Telescope observations
- GRB 150724B: Swift-XRT observations
- GRB 150724B: Swift ToO observations
- Swift Trigger 650221 / IGR J00291+5934: MASTER-IAC OT observations
- Trigger 650221: Swift detection of a IGR J00291+5934
- GRB 150724A: Swift/UVOT Upper Limits
- SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
- GRB 150722A: LCOGT-Sutherland observations
- GRB 150722A: Swift/UVOT Upper Limits
- GRB 150720A: Swift/UVOT Upper Limits
- GRB 150722A: Swift-XRT observations
- GRB 150716A: KAIT Optical Upper Limit
- GRB 150711A: Burakan-ISON optical observations
- GRB 150716A: Swift/UVOT Upper Limits
- GRB 150716A: Continued RATIR Optical Observations
- Swift trigger 649143 is not AX J1619.4-4945 or other astrophysical source
- GRB 150716A: P60 Candidate Optical Afterglow
- GRB 150716A: RATIR Optical Observations
- Trigger 649143: Swift detection of AX J1619.4-4945
- GRB 150710B: Swift-XRT afterglow detection
- GRB 150710B: Swift-XRT and Swift-UVOT observations
- GRB 150711A: Swift/UVOT Upper Limits
- GRB 150711A: Observations from the 2.5m NOT
- GRB 150710B: Swift ToO observations
- GRB 150710A: Swift/UVOT Upper Limits
- Swift-XRT observations of GRB 150710A
- GRB 150710A: RATIR Observations
- Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
- Swift Trigger 648422: Swift-XRT observations
- GRB 150626B: AMI 16 GHz detection of the radio counterpart
- GRB 150702A: MASTER-SAAO inspection
- GRB 150702A: Swift-XRT observations
- GRB 150702A: Swift ToO observations
- Fermi GBM Observations is no longer triggerin on V404 Cyg
- GRB 150622A: Swift-XRT afterglow detection
- 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 150627A: Swift ToO observations
- GRB 150626B: Swift/UVOT Upper Limits
- GRB 150626B: MASTER observations
- GRB 150626A: Swift/UVOT Upper Limits
- V404 Cyg: MASTER Swift, Integral alert observations
- GRB 150622A: Swift-XRT observations
- GRB 150622A: Tiled Swift observations
- V404 Cyg: Fermi GBM observations
- GRB 150616A: Watcher optical upper limit
- Swift triggers again on V404 Cyg