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"3401 results found.
- GRB 090417B: Subaru NIR Observations
- GRB 090407: Swift-XRT refined analysis
- GRB 090404: Swift-XRT Team refined analysis
- Swift/UVOT observations of GRB090401B
- Swift/UVOT observations of GRB090401B
- GRB 090401B: Swift XRT Refined Analysis
- GRB 090328: Swift XRT refined analysis
- GRB 090323: UVOT Detection of Afterglow
- GRB 090323: Swift-XRT refined analysis
- GRB 090323: GROND Detection of the Afterglow and Photo-z
- GRB 090313: Light curve steepening
- GRB 090313 - PAIRITEL NIR detections
- GRB 090313: Swift-XRT refined analysis
- GRB 090313: Faulkes Telescope North observations
- GRB 090306B: Confirmation of the X-ray afterglow
- GRB 090309: Swift-XRT refined analysis
- GRB 090308: Swift-XRT refined analysis
- GRB 090306B: Possible XRT afterglow
- GRB 090307: Swift-XRT afterglow confirmation and analysis
- GRB 090305: Swift-XRT refined analysis
- GRB 090205: Swift-XRT refined analysis
- GRB 090201: Swift-XRT refined analysis
- GRB 090201: Swift-XRT detection of the possible X-ray afterglow
- GRB 090126A: Swift/UVOT Upper Limits
- GRB 090126A: Swift-XRT Refined Analysis
- GRB 090123: Swift XRT refined analysis
- GRB 090118: Swift-XRT observations
- GRB090118 Swift/UVOT upper limits
- GRB090117 Swift/UVOT upper limits
- GRB090117: Swift-XRT detection of a possible candidate afterglow
- GRB 090113: Swift-XRT refined analysis
- GRB 090111: Swift-XRT refined analysis
- GRB 090107B: Swift XRT afterglow confirmation
- GRB 090107B: Swift-XRT detection of possible afterglow
- GRB 090102: Swift XRT refined analysis
- GRB081230: Swift-XRT refined analysis
- GRB 081228: Swift-XRT Team refined analysis
- GRB 081226B: Swift XRT and UVOT upper limits
- GRB 081226: Swift-XRT refined analysis
- GRB 081224: Swift-XRT observation
- GRB 081211B: Further Swift-XRT analysis
- Possible GRB 081211B: Swift/UVOT Upper Limits
- Possible GRB 081211B - Swift-XRT analysis
- GRB 081211: Swift XRT refined analysis
- GRB 081211: Swift/UVOT detection of an optical afterglow
- GRB 081210: Swift-XRT refined analysis
- GRB 081204: Swift XRT afterglow confirmation
- Swift-XRT observations of GRB 081203B
- GRB081203A: Swift-XRT refined analysis
- GRB 081203B: Swift-XRT candidate afterglow.
- GRB 081128: Swift-XRT refined analysis
- GRB 081127: Swift-XRT refined analysis
- GRB 081126: Swift-XRT refined analysis
- GRB 081121: Swift-XRT refined analysis
- GRB 081118: Swift-XRT refined analysis
- GRB 081109A: confirmation of possible detection host galaxy
- Further Swift-XRT observations of the probable GRB 081105.
- GRB 081025: Swift-XRT further analysis
- GRB 081024B: Swift-XRT late-time observations
- GRB 081109A: Swift-XRT refined analysis
- GRB 081028 - PAIRITEL NIR detection
- GRB 081104: refined XRT analysis
- GRB 081102: Swift-XRT refined analysis
- SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
- GRB 081024B: new Swift-XRT observations
- GRB081029: Swift XRT refined analysis
- GRB 081028: Swift-XRT refined analysis
- GRB 081024B: Swift-XRT further observations
- Swift UVOT observations of GRB081024B
- GRB 081025: Swift-XRT position
- GRB 081024B: Swift-XRT observations
- GRB 081016A: Swift-XRT refined analysis
- GRB 081011: Swift XRT refined analysis
- GRB 081016B: Swift-XRT Team refined Analysis
- GRB 081016: Swift-XRT candidate afterglow detection
- GRB 081008: Swift-XRT Refined Analysis
- GRB 081007: Swift-XRT Team refined analysis
- GRB 081003B: Swift-XRT upper limit
- GRB 081003A: Swift-XRT Team position and analysis
- GRB 081001: Swift UVOT Observations
- GRB 081001: Swift-XRT position
- GRB080928: Gemini-South Absorption Redshift
- GRB 080928: Swift-XRT refined analysis
- Swift trigger 325707: Swift-XRT upper limit
- GRB 080919: Swift/UVOT Refined Analysis
- GRB 080919: Swift-XRT refined analysis
- GRB 080916C: IRSF/SIRUS NIR Observation
- GRB 080916C: Swift XRT refined analysis
- GRB 080916B: Swift-XRT refined analysis
- GRB 080916A: Swift XRT refined analysis
- GRB 080915: Swift-XRT afterglow detection and analysis
- GRB 080913: Swift-XRT refined analysis
- GRB 080906: Swift-XRT Refined Analysis
- GRB 080905A: Swift-XRT Refined Analysis
- GRB 080903: Swift-XRT Refined Analysis
- SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
- SGR 0501+4516: Detection of possible optical counterpart
- SGR 0501+4516: WHT observations of the possible near-infrared counterpart
- GRB080825B: Swift/UVOT Upper Limits
- GRB 080828: Swift-XRT detection of a possible X-ray afterglow