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"14 results found.
- GRB 250812A: SVOM/ECLAIRs refined analysis
- GRB 250812A: SVOM/VT optical continued observation
- GRB 250812A: VLT X-shooter spectroscopic redshift confirmation z = 2.571
- GRB 250812A: NTT spectroscopic redshift z = 2.57
- GRB 250812A: Swift/UVOT Detection
- GRB 250812A: EP-FXT counterpart detection
- GRB 250812A: Swift ToO observations
- EP 250812a: GOTO optical upper limit
- GRB 250812A: Kilonova-Catcher optical afterglow detection
- GRB 250812A: SVOM/COLIBRÍ (FM-GFT) optical observations
- GRB 250812A: SVOM/VT optical afterglow confirmation
- GRB 250812A: Swift-XRT afterglow detection
- GRB 250812A: TRT likely optical counterpart detection
- GRB 250812A: SVOM detection of a faint long burst