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"19589 results found.
- GRB 090424: THO optical observations
- GRB 090424: GROND Observations of the Optical/NIR Afterglow
- GRB 090423: Swift/BAT spectral lag results
- GRB 090424: Swift-XRT refined analysis
- GRB 090423: energetic, luminosity and jet break
- Swift/UVOT observations of GRB 090424
- GRB 090424: Enhanced Swift-XRT position
- GRB 090424: Swift-BAT refined analysis
- GRB 090424: Fermi GBM Observation
- GRB 090423: Fermi GBM observation
- GRB 090422: Fermi GBM observation
- GRB 090423: Ep,i - Eiso correlation
- GRB 090424: SDSS Galaxy at the Swift position
- GRB 090424: TNT optical observations
- GRB 090424: ROTSE-III Confimation of Optical Counterpart
- GRB 090424: Swift detection of a burst with an optical counterpart
- GRB 090423: GROND detection and preliminary photo-z
- GRB 090423: Swift-XRT refined analysis
- GRB090423 - Swift/UVOT upper limits.
- GRB 090423: NIR photometry and evidence for spectral break
- GRB 090422: Swift-XRT refined analysis
- GRB090423, RIMOTS optical upper limits
- GRB 090423: Enhanced Swift-XRT position
- GRB 090423: Swift-BAT refined analysis
- GRB 090422: Swift/UVOT Upper Limits
- GRB 090423: Faulkes Telescope South observations
- GRB 090418A: R and I band observation
- GRB 090423: Swift detection of a burst
- GRB 090422: Liverpool Telescope possible candidate
- GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 090422: Swift-BAT refined analysis
- GRB 090422: Enhanced Swift-XRT position
- GRB 090422: Liverpool Telescope observations
- GRB 090422: Swift detection of a burst
- GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
- Swift-BAT trigger 349718 is not a burst
- GRB 090417B: Optical observation
- GRB 090418A: optical observations
- GRB 090419: Swift/UVOT Observations
- GRB 090418B: Faulkes Telescope North observations
- GRB 090418A: Swift/UVOT Observations
- GRB 090417B: Swift/UVOT Upper Limits
- GRB 090417B Correction to the BAT refined analysis position
- GRB 090419: Swift-XRT refined analysis
- Konus-Wind observation of GRB 090418B
- GRB 090419: GROND detection of afterglow candidate
- GRB 090419: Swift-BAT refined analysis
- VLA radio upper limit on GRB 090417B
- GRB 090419: Enhanced Swift-XRT position
- GRB 090418: Swift XRT refined analysis
- GRB 090418A: ROTSE-III Refined Analysis
- GRB 090419: Swift detection of a burst
- GRB 090418B: Detection of a bright burst from Swift-BAT slew data
- GRB 090418: Swift-BAT refined analysis
- GRB 090417B: Swift-XRT refined analysis
- GRB 090418: Enhanced Swift-XRT position
- GRB 090417B: Swift-BAT further refined analysis
- GRB 090418: PAIRITEL NIR detection
- GRB 090418: ROTSE-III Confirmation of Optical Counterpart
- GRB 090418: Swift detection of a burst with optical afterglow
- GRB 090417B: Liverpool Telescope observations
- GRB 090417B: Swift-BAT refined analysis
- GRB 090417A: Swift-BAT refined analysis
- GRB 090417B: Swift detection of a burst
- GRB 090417: 2MASS galaxy within BAT Localization
- GRB 090417: Swift detection of a short burst
- GRB 090410: Suzaku WAM observation of the prompt emission
- GRB 090410: Swift-BAT refined analysis
- GRB 090410: Swift detection of a burst
- Swift-BAT Trigger 348781 is not a GRB
- Swift-BAT Trigger 348720 is not a GRB
- GRB090408, RIMOTS optical upper limits
- Swift-BAT trigger 348781: almost certainly not a burst
- GRB 090408B: MASTER II-Kourovka optical observations
- GRB 090408: Swift detection of a burst
- GRB 090407: Swift-XRT refined analysis
- GRB 090407: Swift UVOT Upper Limits
- GRB 090407: Enhanced Swift-XRT position
- GRB 090407: Swift-BAT refined analysis
- GRB 090407: ROTSE-III Optical Limits
- GRB 090407: Swift detection of a burst
- GRB 090404: millimeter detection
- GRB 090404: nIR observations at Calar Alto
- Swift/UVOT observations of GRB090404
- GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
- GRB 090404: Swift-XRT Team refined analysis
- GRB 090404: Swift-BAT refined analysis
- GRB 090404: Enhanced Swift-XRT position
- GRB 090404: Swift detection of a burst
- GRB 090401A: Suzaku WAM observation of the prompt emission
- GRB 090401B: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 090401B
- GRB 090401B: VLA radio upper limit
- GRB090401B, RIMOTS optical upper limits
- Swift/UVOT observations of GRB090401B
- Swift/UVOT observations of GRB090401B
- GRB 090401B: Swift XRT Refined Analysis
- Konus-Wind observation of GRB 090401A
- GRB 090401B: Enhanced Swift-XRT position
- GRB 090401B: Swift-BAT refined analysis