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"12 results found.
- GRB 250504A: EIRSAT-1 GMOD Detection
- GRB 250504A: Swift-BAT refined analysis
- GRB 250504A: Swift-XRT refined Analysis
- GRB 250504A: VLT/X-shooter upper limits
- GRB 250504A: SVOM/VT upper limit
- GRB 250504A: REM optical/NIR observations
- GRB 250504A: MeerLICHT optical afterglow detection
- GRB 250504A: Fermi GBM Observation
- GRB 250504A: Enhanced Swift-XRT position
- Fermi GRB 250504A: Global MASTER-Net observations report
- GRB 250504A: Swift detection of a burst
- GRB 250504A: Fermi GBM Final Real-time Localization