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"
3050 results found.
- GRB 140508A: Swift-XRT observations
- GRB 140506A: Swift-XRT refined Analysis
- GRB 140502A: Swift-XRT refined Analysis
- GRB 140430A: Swift-XRT refined Analysis
- GRB 140423A: Nishi-Harima NIR Observations
- GRB 140423A: Swift-XRT refined Analysis
- GRB 140419A: Continued RATIR Optical and NIR Observations
- Konus-Wind observation of GRB 140419A
- GRB 140419A: Swift-XRT refined Analysis
- GRB 140414A: Swift/UVOT Upper Limit
- GRB 140414A: Swift-XRT observations
- GRB 140413A: Swift-XRT refined Analysis
- GRB 140412A: Swift-XRT refined Analysis
- Swift Trigger 595345 is not an astrophysical source
- GRB 140408A: Swift-XRT refined Analysis
- GRB 140402A: Swift-XRT observations
- Swift trigger 594286: Is likely a noise trigger
- GRB 140331A: Swift-XRT refined Analysis
- Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
- GRB 140323A: Swift-XRT refined Analysis
- GRB 140320C: Swift/UVOT Upper Limits
- GRB 140320C: Swift-XRT observations
- GRB 140320A: Confirmation of a fading X-ray afterglow
- GRB 140320C: Swift-XRT detection of the X-ray afterglow
- GRB 140320B: Swift-XRT detection of the afterglow
- GRB 140320A: Swift-XRT detection of an afterglow candidate
- Swift Trigger 592558 is not an astrophysical source
- GRB 140318A: Swift-XRT refined Analysis
- GRB 140311C: Swift-XRT and UVOT observations
- GRB 140311A: Swift-XRT refined Analysis
- GRB 140311B: Swift-XRT refined Analysis
- GRB 140304A: Swift-XRT refined Analysis
- GRB 140302A: Swift/UVOT Upper Limits
- GRB 140302A: Swift-XRT refined Analysis
- GRB 140301A: Swift-XRT refined Analysis
- iPTF14yb: Swift-XRT detection
- GRB 140219A: XRT afterglow candidate
- GRB 140221A: Results from Swift XRT tiled observations
- GRB 140219A: results from Swift XRT and UVOT tiled observations
- Swift follow-up of an Integral weak transient
- GRB 140211A: Swift-XRT and UVOT observations
- GRB 140215A: Swift-XRT refined Analysis
- GRB 140213A: Swift/UVOT Observations
- GRB 140213A: Swift-XRT refined Analysis
- GRB140209A: Swift/UVOT observations.
- GRB 140209A: Swift-XRT observations
- GRB 140206A: Swift-XRT refined Analysis
- GRB 140129B: Swift-XRT refined Analysis
- GRB 140129A: Swift-XRT refined Analysis
- GRB 140110A: Second Follow-up Swift-XRT Observation
- GRB 140110A: Further Swift-XRT Observation
- GRB 140114A: Swift-XRT refined Analysis
- GRB 140104B: Further Swift XRT observations
- GRB 140110A: Swift/UVOT Observations
- GRB 140110A: Swift XRT observations
- GRB 140108A: Swift-XRT refined Analysis
- Swift-BAT triggered on KS 1947+300
- GRB 140103A: Swift XRT afterglow confirmation
- GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
- GRB 140103A: Swift-XRT refined analysis
- GRB 140102A: Swift-XRT refined Analysis
- GRB 131231A: Swift-XRT observations
- GRB 131229A: Swift-XRT refined Analysis
- GRB 131227A: Swift-XRT refined Analysis
- GRB 131224A: Swift-XRT observation
- GRB 131209A: Swift XRT and UVOT observations
- GRB 131205A: Swift-XRT refined Analysis
- GRB 131127B: rejection of optical counterpart candidates
- GRB 131202A: Swift-XRT refined Analysis
- GRB 131122A: Swift-XRT Further Observation
- GRB 131128A: Swift-XRT refined Analysis
- GRB 131127A: Swift-XRT refined Analysis
- GRB 131122A: Swift-XRT observations
- GRB 131117A: Swift-XRT refined Analysis
- GRB 131110A: Swift-XRT and UVOT upper limits
- GRB 131108A: Swift-XRT observations
- GRB 131108A: Fermi-LAT refined analysis
- GRB 131108A: Swift detection of a possible X-ray afterglow
- GRB 131031A: Swift-XRT afterglow confirmation
- GRB 131105A: Swift-XRT refined Analysis
- GRB 131103A: Swift-XRT refined Analysis
- GRB 131018B: Further Swift-XRT observations.
- GRB 131031A: Swift-XRT observations
- GRB 131030A: Swift-XRT refined Analysis
- Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
- GRB 131024B: Swift-XRT refined Analysis
- GRB 131024A: Swift-XRT refined Analysis
- GRB 131018B: Swift/UVOT Upper Limits
- GRB 131018B: Swift-XRT observations
- GRB 131018A: Swift-XRT refined Analysis
- GRB 131014A: Swift-XRT refined Analysis
- GRB 131011A: Swift/UVOT Upper Limits
- GRB 131014A: Swift/UVOT Upper Limits
- GRB 131014A: Enhanced XRT position
- Swift-XRT detection of iPTF 13dsw/Fermi403206457
- GRB 131004A: MOSFIRE NIR imaging
- GRB 131004A: Swift-XRT refined Analysis
- GRB 131002B: Swift-XRT Refined Analysis
- GRB 131002A: Swift-XRT refined Analysis
- GRB 130925A: continuing Swift/XRT monitoring