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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"- GRB 140419A: P60 Observations
- GRB 140419A: Swift-XRT refined Analysis
- GRB 140419A: Swift-BAT refined analysis
- GRB 140419A: T24 optical observations
- GRB 140419A: Gemini-N redshift
- GRB 140419A: Enhanced Swift-XRT position
- GRB140419A: UVOT detects fading afterglow in white but not in u filter
- GRB 140419A: CARMA early 3mm detection
- GRB 140419A: RATIR Optical and NIR Observations
- GRB 140419A: ROTSE-III Detection of Optical Counterpart
- GRB 140419A (Swift trigger 596426) : KAIT optical candidate
- GRB 140419A: Swift detection of a burst with optical afterglow
- Konus-Wind observation of GRB 140416A
- IPN Triangulation of GRB 140416A (long/very intense)
- GRB 140416A: Fermi GBM detection
- GRB 140414A: Swift/UVOT Upper Limit
- GRB 140414A: Swift-XRT observations
- GRB 140414A: TNG optical observations
- GRB 140414A: Swift-BAT refined analysis
- GRB 140414A: Short burst found in ground analysis of BAT slew data
- GRB 140413A: Swift/UVOT Observations of the Optical Afterglow
- GRB 140412A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 140413A
- GRB 140413A: Swift-XRT refined Analysis
- GRB 140413A: Swift-BAT refined analysis
- GRB 140412A: Swift-XRT refined Analysis
- GRB 140412A: Swift-BAT refined analysis
- GRB 140413A: TAROT La Silla observatory optical observations
- GRB 140413A: Swift-XRT observations
- GRB 140412A: Enhanced Swift-XRT position
- GRB 140413A: GROND afterglow candidate
- Swift Trigger 595616: a possible GRB
- GRB 140412A: Swift detection of a burst
- GRB 140408A: 1.5m OSN optical upper limit
- Swift Trigger 595345 is not an astrophysical source
- Swift-BAT trigger 595162 is noise
- GRB 140408A: MITSuME Akeno Optical observation
- Fermi418277210: iPTF optical observations
- GRB 140408A: RATIR Optical Upper Limits
- GRB 140408A: Swift-BAT refined analysis
- GRB 140408A: GROND Detection of an Afterglow Candidate
- GRB 140408A: Swift/UVOT Upper Limits
- GRB 140408A: Swift-XRT refined Analysis
- GRB 140408A: MITSuME Okayama upper limits
- GRB 140408A: Enhanced Swift-XRT position
- GRB 140408A: Fermi GBM detection
- Swift Trigger 595162: a possible GRB
- GRB 140408A: Swift detection of a burst
- GRB 140406A: Fermi GBM observation
- GRB 140402A: Deep limit on the optical afterglow from Magellan observations
- GRB 111225A: Archeological redshift of the Christmas Burst 2011 from GTC
- GRB 140402A: Swift/UVOT Upper Limits
- GRB 140331A: Continued RATIR Optical and NIR Observations
- GRB 140402A: Swift-XRT observations
- GRB 140402A: MASTER optical observations
- GRB 140402A BAT refined analysis
- GRB 140402A : Xinglong TNT upper limit
- GRB 140402A: Marginal BAT detection
- GRB 140402A: Fermi GBM detection
- GRB 140402A: Fermi-LAT detection of a burst
- Swift trigger 594286: Is likely a noise trigger
- GRB 140219A: Correction to GCN 15885 (Suzaku-WAM fluence)
- GRB 140330A: Fermi GBM observation
- GRB 140331A: Swift-XRT refined Analysis
- GRB 140301A: Zadko observatory - Gingin optical observations
- GRB 140331A: Swift-BAT refined analysis
- Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
- GRB 140331A: Swift/UVOT Upper Limits
- GRB 140302A: TAROT La Silla observatory optical observations
- GRB 140323A: Zadko observatory - Gingin optical observations
- GRB 140330A: intense and persistent gamma-ray emission detected by AGILE
- GRB 140331A: Zadko observatory - Gingin optical observations
- Konus-Wind observation of GRB 140330A
- GRB 140129B: AAO optical upper limit
- GRB 140129A: Mondy optical observations
- GRB 140331A: MITSuME Okayama upper limits
- GRB 140331A: Enhanced Swift-XRT position
- IPN triangulation of GRB 130330A
- GRB 140331A: RATIR Optical and NIR Observations
- GRB 140331A: Swift detection of a burst
- GRB 140330A: Fermi-LAT Detection
- GRB 140329A: Fermi-LAT detection
- Konus-Wind observation of GRB 140329A
- IPN Triangulation of GRB 140329A
- MAXI ID=745548350 is UV Ceti
- GRB 140320D: MASTER optical observations
- GRB 140329A: Fermi GBM observation of a bright burst
- Swift trigger 593744: detection of a flare from UV Cet
- GRB 140320D: Suzaku WAM observation of the prompt emission
- GRB 140323A : Suzaku WAM observation of the prompt emission
- Fermi Gamma-ray Burst Monitor trigger 417486540 / 140326020 is not a GRB
- GRB 140226A/iPTF14yb: Mondy optical observations
- GRB 140320C: Mondy optical observations and afterglow confirmation
- Konus-Wind observation of GRB 140323A
- GRB 140323A: Fermi-LAT detection
- GRB 140323A: Swift-XRT refined Analysis
- GRB 140323A: Fermi GBM observation
- GRB 140323A: BOOTES-3 optical upper limit.
- GRB 140323A: Swift/UVOT Upper Limits
- GRB 140323A: Swift-BAT refined analysis