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"8297 results found.
- GRB 090417B: Swift detection of a burst
- Swift-BAT trigger 348781: almost certainly not a burst
- GRB 090407: Swift detection of a burst
- GRB 090404: Swift detection of a burst
- GRB 090401B: Swift-BAT refined analysis
- GRB 090401B: Swift detection of a burst
- GRB 090324: Suzaku WAM observation of the prompt emission
- GRB 090328: Gemini South Redshift
- GRB 090328: Swift UVOT observations
- GRB 090323: WSRT Radio Detection
- GRB 090328: Updated position/optical afterglow candidate
- GRB 090328: Possible Swift/XRT detection
- GRB 090323: TLS detection at 5 days, no break
- GRB 090323: UVOT Detection of Afterglow
- GRB 090324: SuperAGILE Localization of a Long GRB
- GRB 090323 Gemini-South Redshift
- GRB 090313: WSRT Radio Detection
- A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
- GRB 090313: WSRT Radio Observations
- GRB 090313: Gemini-S photometry
- GRB 090313: Swift-XRT refined analysis
- GRB 090313, GROND observations
- GRB 090313 OA candidate
- GRB 090205: Zadko Telescope late-time observations
- GRB 090309: Swift detection of a burst
- GRB 090307B: Fermi GBM detection
- GRB 090308: Swift detection of a burst
- Swift Trigger 345551 is probably not a GRB
- GRB090305: GMOS-S Candidate Optical Afterglow
- GRB 090305: Swift detection of a short burst
- GRB 090227: Fermi GBM detection
- SGR J1550-5418
- GRB 090205: Swift/UVOT Upper Limits
- GRB 090205: VLT candidate afterglow
- GRB 090205: Swift detection of a burst
- GRB090201: Swift UVOT upper limits
- GRB 090201: VLT NIR observations
- GRB 090201: VLT afterglow candidate
- GRB 090129: Swift detection of a burst
- GRB 090126: SuperAGILE Localization of a Long GRB
- Konus-Wind detection of very bright SGR-like burst on January 25, 2009
- GRB 090118: no afterglow candidate
- GRB 090123: Swift detection of a burst
- Trigger 340734: Swift detection of a possible short burst
- GRB 090118: Subaru NIR Observation
- GRB 090118: KPNO 4m 2nd Epoch Observations
- GRB 090118: KPNO 4m Detection of Candidate Afterglow
- GRB090118 Swift/UVOT upper limits
- GRB 090118: Possible burst detection from Swift-BAT slew data
- GRB090117: Swift-XRT detection of a possible candidate afterglow
- GRB 090117 - SuperAGILE Localization of a long GRB
- GRB 090113: LOAO Detection Limits in R, I, z, Y-band
- GRB 090113: Swift detection of a burst
- GRB 090111: Swift detection of a burst
- GRB 090102: WSRT Radio Observations
- GRB 090107B: Swift/UVOT Observations
- Swift UVOT observations of GRB 090102
- GRB 090102: Swift detection of a burst with an optical counterpart
- GRB 081230: GROND confirmation of the afterglow
- GRB 081230: Swift detection of a burst
- GRB 081228: GROND confirmation of the optical/NIR afterglow
- GRB 081228: Swift detection of a burst
- GRB 081226B: Swift XRT and UVOT upper limits
- GRB 081224: Suzaku WAM observation of the prompt emission
- GRB 081226: GROND afterglow candidate
- GRB 081222: MITSuME optical observation
- GRB 081224: Fermi GBM Detection & LAT Localization
- GRB 081222:Optical afterglow observation
- GRB081222: REM candidate afterglow
- GRB 081222: Swift detection of a burst with a bright optical afterglow
- GRB 081221: Swift detection of a burst
- GRB 081118: Zadko observations
- GRB 081211B(?): Possible burst detection from Swift-BAT slew data
- GRB 081211: Swift detection of a burst
- GRB 081210: Swift detection of a burst with optical afterglow
- GRB 081128: afterglow observations
- GRB 081128: Optical afterglow observations
- GRB 081204: GROND Observations
- GRB 081204: Swift XRT afterglow confirmation
- GRB 081204: Swift XRT afterglow candidate
- GRB 081203B: Swift-XRT candidate afterglow.
- GRB 081203A: Burst detection from Swift-BAT slew data
- GRB 081203: Swift detection of a burst with a bright optical counterpart
- Trigger 335971: Swift possible detection of a burst
- GRB 081128: Liverpool Telescope afterglow confirmation
- GRB 081128: Swift detection of a burst
- GRB 081127: Swift detection of a burst
- GRB 081126: Swift detection of a burst
- GRB081121: Swift/UVOT observations
- GRB 081121: ROTSE-III Detection of Optical Counterpart
- GRB 081118: VLT redshift
- GRB 081118: optical afterglow candidate
- GRB 081118: Swift detection of a burst
- GRB 081110: Fermi GBM detection
- GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 081109: Swift detection of a burst
- GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
- GRB 081102: Swift detection of a burst
- Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
- GRB 081024B: new Swift-XRT observations