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"- GRB 101219A: ROTSE-III Optical Limits
- GRB 101219A: Swift detection of a short hard burst
- Request for Supernova related data for GRB 101023A
- GRB 101213A : Suzaku WAM observation of the prompt emission
- Redshift solution(s) for GRB101213A from Swift-XRT data
- Konus-Wind observation of GRB 101213A
- XRF 101117A, RIMOTS optical upper limits
- GRB 101213A: Fermi GBM observation
- GRB 101213A, Swift-BAT refined analysis
- GRB 101213A: Swift-XRT refined Analysis
- GRB 101213A: Swift/UVOT Upper Limits
- GRB 101213A: Enhanced Swift-XRT position
- GRB 101213: object within the X-ray error circle
- GRB 101213A: Swift detection of a burst
- GRB101204A: Swift/UVOT observations
- GRB 101204A: Swift-XRT refined Analysis
- GRB101204A GROND Detection of the Optical/NIR Afterglow
- GRB 101204A Afterglow Candidate, VATT Observations
- GRB 101129A : Suzaku WAM observation of the prompt emission
- GRB 101204A Swift-XRT/UVOT afterglow candidate
- Konus-Wind observation of GRB 101130A
- GRB 101204A detected in ground analysis of BAT data
- Konus-Wind observation of GRB 101129A
- IPN Localization of GRB101130 (possible short duration burst)
- GRB 101129A SHB found by IPN and in ground analysis of BAT data
- GRB101030A
- GRB 101201A: Fermi GBM observation
- GRB 101201A: Swift-XRT refined Analysis
- GRB 101201A: Swift/UVOT Detection
- GRB 101201A: GROND Detection of the Optical/NIR Afterglow
- GRB 101201A detected in ground analysis of BAT data
- Swift detection of MAXIJ1409-619
- GRB 101123A: ROTSE optical observations
- GRB 101123A: MASTER prompt optical observations
- Konus-Wind observation of GRB 101123A
- IPN triangulation of bright GRB 101123A
- GRB 101123A: Fermi GBM detection
- Optical observation of GRB 101024A
- GRB 101117B: GROND Upper limits
- GRB 101117B: Swift/UVOT Observations of the Optical Afterglow
- GRB 101112A: OSN and BTA observations
- XRF 101117A: Palomar Transient Factory Observations
- GRB 101117B: Swift-XRT refined analysis
- GRB101114A: Swift/UVOT Upper Limits
- GRB 101114A: Confirmation of the X-ray afterglow
- GRB 101117B: Swift-BAT refined analysis
- GRB 101117B: Enhanced Swift-XRT position
- GRB 101117B: Swift/UVOT Discovery of an Optical Afterglow
- GRB 101117B: Swift detection of a burst
- XRF101117A: MAXI/GSC detection of a short X-ray transient
- GRB 101114A: GROND Upper limits
- Konus-Wind observation of GRB 101114A
- Fermi GBM detection of a burst from a galactic source
- GRB 101114A: Swift-XRT candidate afterglow detection and analysis
- GRB 101114A, Swift-BAT GRB detected by ground processing
- Possible detection of INTEGRAL burst GRB 101112A by the EVLA
- GRB 101112A: Fermi GBM detection
- GRB 101112A: optical observations
- GRB 10112A: MASTER optical observations
- Konus-Wind observation of GRB 101112A
- GRB 101112A - XRT source detection/analysis
- GRB 101112A: BOOTES-2/TELMA optical afterglow candidate
- GRB101112A: Liverpool Telescope Afterglow Candidate
- GRB 101112A: a long GRB detected by INTEGRAL
- GRB 100906A: optical observations
- GRB 090113, the review of the sky area in plate archives
- GRB 101030A : MOA optical observation
- GRB 101030A: GROND optical/NIR afterglow candidate
- GRB 101030A : Swift XRT refined analysis
- GRB 101030A: Swift/UVOT Upper Limits
- GRB 101030A: Swift-BAT refined analysis
- GRB 101030A: Enhanced Swift-XRT position
- GRB 101030A: Swift detection of a burst
- GRB 090111, the review of the sky area in plate archives (1976-1996)
- Konus-Wind observation of GRB 101023A
- GRB 101024A: GROND optical/NIR observations
- GRB 101024A: Zadko observatory - Gingin. Optical observations refined analysis
- GRB 101024A: Swift XRT refined analysis
- GRB 101024A: Zadko observatory - Gingin. Optical observations
- GRB 101023A: miniTAO/ANIR NIR detection
- GRB 101024A: Fermi GBM observation
- GRB 101023A: Fermi GBM observation
- GRB101024A: Swift/UVOT
- GRB 101024A: Swift-BAT refined analysis
- GRB 101024A: GRAS06 optical observations
- GRB 101024A: Enhanced Swift-XRT position
- Swift/UVOT observations of GRB101023A
- GRB 101024A: Swift detection of a burst with an optical afterglow
- GGRB 101023A: GROND detection of the optical-NIR afterglow
- GRB 101023A: Swift-XRT Team Refined Analysis
- GRB 101023A: Swift-BAT refined analysis
- GRB 101023A: Gemini discovery of optical afterglow
- GRB 101023A: Enhanced Swift-XRT position
- GRB 101023A: REM NIR observations
- GRB 101023A: Swift detection of a burst
- GRB 101011A: miniTAO/ANIR NIR upper limits
- GRB 101020A: MASTER prompt and afterglow limit
- GRB 101020A: BOOTES2 follow-up and limit
- GRB 101020A: MASTER polarization optical observations
- GRB 101020A, Swift-BAT refined analysis