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"9 results found.
- GRB 250101A: MASTER earlier OT observations with SOSS emission features
- GRB 240101A: 1.3m DFOT optical observations
- GRB 240101A: Swift-BAT refined analysis
- GRB 240101A: Terskol Zeiss-2000 optical observations
- GRB 240101A: Swift/UVOT Upper Limits
- GRB 240101A: Swift-XRT refined Analysis
- GRB 240101A: KAIT Optical Upper Limit
- GRB 240101A: Enhanced Swift-XRT position
- GRB 240101A: Swift detection of a burst