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"3402 results found.
- GRB 220527A: Swift/UVOT detection
- GRB 220527A: Swift-XRT afterglow detection
- Fermi GRB 220523A: Global MASTER-Net observations report
- GRB 220521A: Swift-XRT refined Analysis
- GRB 220518A: Swift-XRT refined Analysis
- Continued Chandra monitoring of GW170817 at ~4.8 yr post-merger
- GRB 220514B: Swift-XRT observations
- GRB 220511A: Swift-XRT afterglow detection
- GRB 220511A: Swift-XRT observations
- GRB 220506A: Swift-XRT afterglow detection
- GRB 220430A: Swift-XRT refined Analysis
- GRB 220426A: Swift-XRT and UVOT observations
- GRB 220427A: Swift-XRT refined Analysis
- GRB 220418B: Swift-XRT observations
- GRB 220403C: Further Swift-XRT observations
- GRB 220412B: Swift-XRT observations
- GRB 220412A: Swift-XRT refined Analysis
- GRB 220403C: Swift-XRT observations
- GRB 220408A: Swift-XRT refined Analysis
- Chandra upper limit at the location of GRB 220408A
- GRB 220403B: Swift-XRT refined Analysis
- GRB 220325A: Swift-XRT refined Analysis
- GRB 220319A: Swift-XRT refined Analysis
- GRB 220310C: Swift-XRT observations
- GRB 220306B: Swift-XRT refined Analysis
- GRB 220305A: Swift-XRT refined Analysis
- GRB 220302A: Swift-XRT refined Analysis
- GRB 220219B: Swift-XRT observations
- ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
- ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
- IceCube-220205B - IceCube observation of a high-energy neutrino candidate track-like event
- GRB 220117B: Swift-XRT refined Analysis
- GRB 220117A: Swift-XRT refined Analysis
- Confirmation of the X-ray afterglow of GRB 220107B
- GRB 220107A: Swift/UVOT Detection
- GRB 220107B: Swift-XRT afterglow detection
- GRB 220107A: Swift-XRT afterglow detection
- GRB 220101A: Swift-XRT refined Analysis
- GRB 211229A: Swift-XRT and UVOT observations
- Fermi GRB 211229B: Global MASTER-Net observations report
- GRB 211227A: Swift-XRT refined Analysis
- GRB 211221A: Swift-XRT refined Analysis
- GRB 211106A: XMM-Newton monitoring campaign detections
- GRB 211211A: Swift-XRT refined Analysis
- Chandra observation of GW170817 at ~1573 days since merger (Epoch 1 of 4)
- GRB 211207A: Swift-XRT refined Analysis
- GRB 211129A: Swift-XRT refined Analysis
- Chandra observations of GRB 210905A
- GRB 211106A: Swift/UVOT upper limits
- GRB 211107B: Swift-XRT afterglow detection
- GRB 211106A: Swift-XRT afterglow detection
- GRB 211107B: Swift-XRT observations
- GRB 211106A: Swift-XRT observations
- Swift Trigger 1082569 is probably not a GRB
- GRB 211024A: Swift-XRT observations
- GRB 211018A: Swift-XRT observations
- GRB 211025A: Swift-XRT refined Analysis
- GRB 211024B: CAHA 2.2m Detection; ultra-long GRB?
- GRB 211024B: Swift-XRT refined Analysis
- GRB 211023B: Swift-XRT refined Analysis
- GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
- GRB 210928A: Swift-XRT refined Analysis
- GRB 210930A: Swift/UVOT Upper Limits
- GRB 210930A: Swift-XRT refined Analysis
- GRB 210919A: Swift-XRT refined Analysis
- GRB 210912A: Swift-XRT refined Analysis
- GRB 210826A: further Swift-XRT observations
- Fermi trigger No 652927551: Global MASTER-Net observations report
- GRB 210905A: Swift-XRT refined Analysis
- GRB 210901A: Swift-XRT refined Analysis
- GRB 210827A: further Swift-XRT observations
- GRB 210827A: Swift-XRT observations
- GRB 210826A: Swift-XRT observations
- GRB 210826A: Fermi-LAT detection
- GRB 210824A: Swift-XRT refined Analysis
- GRB 210822A: Swift-XRT refined Analysis
- GRB 210820A: Swift-XRT refined Analysis
- GRB 210818A: Swift-XRT refined Analysis
- GRB 210802A: Further Swift/XRT observation and afterglow confirmation
- GRB 210807C: Swift-XRT refined Analysis
- GRB 210807A: Swift-XRT refined Analysis
- GRB 210802A: Swift-XRT afterglow detection
- GRB 210731A: Swift-XRT refined Analysis
- GRB 210726A: Chandra detection of the X-ray afterglow
- GRB 210730A: Swift-XRT refined Analysis
- GRB 210726A: Swift-XRT refined Analysis
- GRB 210725B: Swift-XRT refined Analysis
- GRB 210725A: Swift-XRT refined Analysis
- GRB 210724A: Swift-XRT refined Analysis
- GRB 210723A: Swift-XRT refined Analysis
- GRB 210722A: Swift-XRT refined Analysis
- GRB 210712A: Swift-XRT refined Analysis
- GRB 210706A: Swift/XRT afterglow confirmation
- GRB 210708A: Swift-XRT refined Analysis
- GRB 210706A: Swift-XRT afterglow detection
- GRB 210704A: Swift-XRT afterglow detection
- GRB 210702A: Swift-XRT refined Analysis
- GRB 210626A: Swift/XRT afterglow confirmation
- GRB 210626A: Swift-XRT afterglow detection
- GRB 210622A: Swift-XRT observations