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"27778 results found.
- GRB 110905A: Potential BAT trigger on MAXI J1836-194
- GRB 110905A: Swift detection of a burst
- GRB 110903A: Swift/UVOT Upper Limits
- GRB 110903A: Swift-XRT observations
- GRB 110820A: optical upper limit
- SGR Swift J1834.9-0846: Correction to the Swift-BAT refined spectral analysis
- Trigger 502024: Swift detection of KS 1741-293
- SGR Swift J1834.9-0846: Swift-BAT refined analysis of trigger 501752
- Swift detection of an SGR burst from Swift J1834.9-0846
- GRB 110825A: GMG optical observation
- GRB 110827A, Swift-BAT refined analysis
- GRB 110827A: Swift detection of a burst
- GRB110825A: Swift target of opportunity observation
- IPN triangulation of GRB110825A (very intense, long-duration)
- Swift-BAT Trigger 501485 is noise
- Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
- Swift J1834.9-0846: Precise X-ray Position and the Confirmation of its Spin Period
- IPN triangulation of GRB 110820B (very long duration, extremely intense)
- GRB 110820A: Swift/UVOT Upper Limits
- GRB 110820A: Swift-XRT refined Analysis
- GRB 110820A: Swift-BAT refined analysis
- GRB 110820A: Enhanced Swift-XRT position
- GRB 110820A: CrAO optical upper limit
- GRB 110820A: MASTER-NET observations
- GRB 110820A: Swift detection of a burst
- GRB 110818A: Fermi GBM observation
- GRB 110818A: Swift/UVOT Upper Limits
- GRB 110818A: Enhanced Swift-XRT position
- GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
- GRB 110818A: Swift-XRT refined Analysis
- GRB 110815A: Swift-XRT and UVOT refined Analysis
- GRB 110818A, Swift-BAT refined analysis
- GRB 110818A: Swift detection of a burst
- IPN triangulation of GRB110815A (long, intense)
- GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
- GRB 110801A: optical observations at Mt. Terskol observatory
- Reprocessed enhanced Swift-XRT positions and GRB products: update
- SGR 1834.9-0846/ GRB 110807A, I-band observations
- IPN triangulation of GRB 110808B (short/hard/intense)
- RXTE Discovery of the Spin Period of Swift J1834.9-0846
- GRB 110808A: Swift/UVOT Detection
- Swift Trigger 458942 is probably not a burst
- GRB 110808A: Swift-BAT refined analysis
- GRB 110808A: Swift-XRT refined Analysis
- SGR J1834.9-0846: A Neutron Star in W41?
- Swift SGR 1834.9-0846: Swift-BAT refined analysis
- GRB 110808A: Enhanced Swift-XRT position
- GRB 110808A: Swift detection of a burst with optical counterpart
- Fermi GBM detection of a SGR-like burst
- GRB 110807A: Swift detection of a burst or a posible new SGR
- GRB 110726A: two epochs of SAO RAS optical observations
- Reprocessed enhanced Swift-XRT positions and GRB products
- IPN triangulation of GRB110802A (short/hard burst)
- GRB 110731A : Suzaku WAM observation of the prompt emission
- GRB 110726A: Swift-XRT refined Analysis
- GRB110731A: MOA optical observations of the steeply fading afterglow
- GRB 110801A: MASTER OT observations
- GRB 110801A: Swift-BAT refined analysis
- Swift/UVOT observations of GRB110801A
- GRB 110801A: Swift-XRT refined Analysis
- GRB 110801A: Enhanced Swift-XRT position
- AXP 4U 0142+61: Fermi GBM detection
- GRB 110801A: TLS Optical afterglow confirmation
- GRB 110801A: ROTSE-III Detection of re-brightening from OT
- GRB 110801A: Swift detection of a burst with an optical counterpart
- GRB 110731A / EVLA upper limits
- GRB 110731A: Swift-XRT refined Analysis
- Konus-Wind observation of GRB 110731A
- GRB110731A: Swift/UVOT Observations
- GRB 110731A: Fermi GBM observation
- GRB 110731A: Enhanced Swift-XRT position
- Fermi-LAT Detection of GRB110731A
- GRB 110731A: Swift-BAT refined analysis
- GRB 110731A: FTN+FTS afterglow observations
- GRB 110731A: Swift detection of a burst with an optical counterpart
- GRB 110721A: Swift observations of afterglow candidate
- AXP 4U 0142+61: Swift-BAT refined analysis
- GRB 110726A: optical upper limit in CrAO
- Swift detection of a SGR-like burst from the AXP 4U 0142+61
- Swift triggers 458268 and 458269 are not astrophysical
- GRB 110726A: ROTSE-III refined analysis, fast decay in early phase
- GRB 110726A: Further Swift/UVOT Observations
- GRB 110726A: Swift-BAT refined analysis
- GRB 110726A: Enhanced Swift-XRT position
- GRB 110726A: Swift/UVOT Detection
- GRB 110726A: Liverpool Telescope observations
- GRB 110726: ROTSE-III Detection of Optical Counterpart
- GRB 110726A: Swift detection of a burst
- GRB 110721A: Preliminary Swift/UVOT Upper Limits
- GRB 110721A: potential counterpart candidate
- Konus-Wind observation of GRB 110721A
- GRB 110709B / EVLA detection of radio counterpart
- GRB 110721A: Fermi-LAT detection
- GRB 110721A: Fermi GBM detection
- Recent GCN/Swift-BAT Slew Burst Position notices are due to playback debugging
- GRB110715A: spectral lag analysis
- GRB 110715A : Suzaku WAM observation of the prompt emission
- GRB 110719A: GRT Optical Observation
- GRB 110719A: optical limit by "Pi of the Sky"
- GRB 110719A: z-band upper limit