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"13 results found.
- GRB 250903A: SVOM/ECLAIRs refined analysis
- GRB 250903A: Swift-XRT afterglow detection
- GRB 250903A: Swift/UVOT detection
- IceCube-Cascade 250903A: Upper limits from a search for additional neutrino events in IceCube
- GRB 250903A: Swift-XRT observations
- GRB 250903A: VLT X-shooter spectroscopic redshift z = 1.590
- GRB 250903A: EP-FXT counterpart detection
- GRB 250903A: LCO optical observation
- GRB 250903A: LCO optical afterglow detection
- GRB 250903A: SVOM/VT optical confirmation with VHF data
- Subject GRB 250903A: SVOM/MXT afterglow detection
- GRB 250903A: TRT optical counterpart detection
- GRB 250903A: SVOM detection of a burst