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"21267 results found.
- GRB 100513A, RIMOTS optical upper limits
- GRB 100513A: Enhanced Swift-XRT position
- GRB 100513A: SARA-N Upper Limit
- GRB 100513A: Swift detection of a burst
- GRB 100510A: Fermi GBM detection/observation
- GRB 100511A: Fermi GBM detection/observation
- GRB 100511A: Super-LOTIS early observations
- Swift-BAT trigger 421695 is likely not astrophysical
- GRB100504A: Optical upper limits at IAO
- GRB 100511A, RIMOTS optical upper limits
- Trigger 421695: Swift detection of a possible burst
- GRB100503A: Suzaku WAM observation of the prompt emission
- GRB 100508A: GROND Detection of the optical afterglow
- GRB 100508A: Enhanced Swift-XRT position
- GRB100508A: Swift/UVOT Detection of the Afterglow
- GRB 100508A: ROTSE-III Optical Limits
- GRB 100508A: Swift detection of a burst
- GRB 100418A: Keck imaging
- GRB 100418A: RTT150 optical observations
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- GRB 100504A: Swift/UVOT Observations
- GRB 100504A: Enhanced Swift-XRT position
- GRB 100504A: GROND Upper limits
- GRB 100504A: SARA-South Upper Limit
- GRB 100503A: Fermi GBM detection
- GRB 100504A: Swift detection of a burst
- INTEGRAL observations of Swift GRB trigger 421072
- GRB100423A : Suzaku WAM observation of the prompt emission
- Trigger 421072: Possible Swift detection of a GRB or transient
- GRB 100420A: Terskol optical upper limit
- GRB 100427A: Swift XRT and UVOT Upper Limits
- GRB 100414A : EVLA Radio Detection
- GRB 100414A : WSRT Radio Detection
- Konus-Wind observation of GRB 100423A
- GRB 100423A: CrAO optical observations
- GRB 100418A: Terskol optical observations
- GRB 100424A: CrAO optical observations
- GRB 100424A: NIR Afterglow Confirmation
- GRB 100424A: Gemini/NIRI H-band observations
- GRB100425A: Swift/UVOT Upper Limits
- GRB 100424A: Swift/UVOT Upper Limits
- GRB 100424A: Liverpool Telescope Upper Limits
- GRB 100425A: Enhanced Swift-XRT position
- GRB 100425A: GROND afterglow observation
- GRB 100424A: Gemini/NIRI Candidate Afterglow
- GRB 100424A: D50 optical limits
- GRB 100425A: candidate optical afterglow from the VLT
- GRB100424A: MITSuME optical upper limits
- GRB100423A: MITSuME optical upper limits
- GRB 100424A : Lulin early z'-band upper limit
- GRB 100424A: GROND Upper Limits
- GRB 100424A: PAIRITEL NIR Upper Limits
- GRB 100425A: Swift detection of a burst
- GRB 100424A: NOT optical observations
- GRB 100424A: Enhanced Swift-XRT position
- GRB 100424A: Swift detection of a burst
- GRB 100420A: GRT Optical Observation
- Swift Trigger 420256: D50 optical limits
- GRB 100423B: Fermi GBM detection
- Swift Trigger 420256: IAC80 R-band observations
- Swift Trigger 420256: BOOTES-2 observations
- Swift Trigger 420256: ROTSE-III Optical Limits
- Trigger 420256: Swift detection of a possible GRB
- GRB 100423A: GROND discovery of afterglow
- GRB100418A: REM possible afterglow detection
- GRB 100418A: Continuing Swift/UVOT Observations
- GRB100420A: MITSuME optical upper limits
- GRB 100414A: CFHT optical observations
- GRB 100420A: Swift/UVOT Upper Limits
- GRB 100420A: Enhanced Swift-XRT position
- GRB 100418A: SARA second epoch
- GRB 100420A: SARA Upper Limits
- GRB 100418A: optical observations
- GRB 100418A: SMA submm detection
- GRB 100420A: ROTSE-III Optical Limits
- GRB 100420A: Swift detection of a burst
- GRB 100418A: Swift/UVOT Observations
- GRB 100418A: Gemini-N redshift confirmation
- GRB100418A: VLT/X-shooter redshift and photometry
- GRB 100418A: SARA observations
- GRB 100418A: GROND observations; missing author list added
- GRB 100418A: GROND observations
- GRB 100418A: Enhanced Swift-XRT position
- GRB 100418A: ROTSE-III Optical Limits
- GRB 100418A: Swift detection of a burst with a possible optical afterglow
- GRB 100414A: Suzaku WAM observation of the prompt emission
- GRB 100414A: Swift/UVOT Observations
- GRB 100414A: GROND Detection of the Optical Afterglow
- GRB 100414A: Gemini-N candidate and redshift
- GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
- GRB 100413A: Suzaku WAM observation of the prompt emission
- GRB 100414A: Palomar Transient Factory Observations
- GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
- Konus-Wind observation of GRB 100414B
- GRB 100414A: Fermi GBM detection
- GRB100414A: Fermi LAT detection
- GRB 100413B : Swift detection of a burst
- GRB 100413A: GROND Upper limits
- GRB 100413A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB 100413A