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"19538 results found.
- 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
- Swift/UVOT detection of GRB090401B
- GRB 090401B: Swift detection of a burst
- GRB 090401, Swift-BAT refined analysis
- GRB 090401: Swift detection of a burst
- GRB 090328: Swift XRT refined analysis
- GRB 090328: Swift UVOT observations
- GRB 090328: Updated position/optical afterglow candidate
- GRB 090328: Possible Swift/XRT detection
- Fermi LAT and GBM detections of GRB090328
- GRB 090323: UVOT Detection of Afterglow
- GRB 090323: Swift-XRT refined analysis
- GRB 090323: GROND Detection of the Afterglow and Photo-z
- GRB 090323: Possible XRT Counterpart
- IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
- Further Swift/UVOT observations of GRB 090313
- GRB 090313: detection with CARMA in 3mm band
- GRB 090313: TAROT La Silla observatory optical detection
- GRB 090313: Zadko Telescope observations
- GRB 090313 - PAIRITEL NIR detections
- GRB 090313: Swift-XRT refined analysis
- GRB 090313: Swift/UVOT upper limits
- GRB 090313: Faulkes Telescope North observations
- GRB 090306B: Confirmation of the X-ray afterglow
- GRB 090313: Swift-BAT refined analysis
- GRB 090313, GROND observations
- GRB 090309, Swift-BAT lag analysis
- GRB 090313: Swift detection of a burst
- GRB 090313: Swift detection of a burst
- Swift trigger 346250 is probably not a burst
- GRB 090309A: GROND upper limits
- GRB 090307A: TAROT Calern observatory optical observations
- GRB 090309: Swift/UVOT Upper Limits
- GRB 090309: Swift-XRT refined analysis
- GRB 090309: Enhanced Swift-XRT position
- GRB 090306B: INTEGRAL SPI-ACS light curve
- GRB 090309, Swift-BAT refined analysis
- GRB 090308: GROND observations
- GRB 090308: Gemini GMOS Observations
- GRB 090309: Swift detection of a burst
- GRB 090308: Swift/UVOT Upper Limits
- GRB 090307: GROND Upper Limits
- GRB 090306B: GROND Upper Limits
- GRB 090305C: Suzaku WAM observation of the prompt emission
- GRB 090308: Swift-XRT refined analysis
- Radio observation of GRB 081007 with ATCA
- ATCA observation of SGR J1550-5418
- GRB 090308: Swift-BAT refined analysis
- GRB 090308: Swift detection of a burst
- GRB 090306B: Possible XRT afterglow
- GRB 090307: Swift-XRT afterglow confirmation and analysis
- GRB 090307: Swift-BAT refined analysis of trigger 345551
- GRB 090306B: Burst detection from Swift-BAT slew data
- Swift Trigger 345551 is probably not a GRB