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.
Lucene Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"11 results found.
- GRB 250321A: Swift-BAT refined analysis
- GRB 250321A: Swift-XRT refined Analysis
- EP 250321A: Optical counterpart detection by LCO.
- GRB 250321A: Swift/UVOT Upper Limits
- Swift GRB 250321A: Global MASTER-Net observations report
- Fermi GRB 250321A: Global MASTER-Net observations report
- GRB 250321A: GOTO optical upper limits
- GRB 250321A: Swift-XRT localisation
- GRB 250321A: Fermi GBM Observation
- GRB 250321A: Swift detection of a burst
- GRB 250321A: Fermi GBM Final Real-time Localization