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"15 results found.
- GRB 250402A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations.
- GRB 250402A: Swift/BAT-GUANO localization skymap of a burst
- GRB 250402A: Mondy optical observations
- GRB 250402A: Swift/UVOT Upper Limits
- GRB 250402A: EP-FXT afterglow detection
- GRB 250402A: NUTTelA-TAO Early Optical Limits
- GRB 250402A: Fermi GBM Observation
- GRB 250402A: Swift-XRT observations
- GRB250402A: SVOM/COLIBRÍ (FM-GFT) Detection of the Optical Counterpart
- GRB 250402A: VLT/FORS2 spectroscopic redshift z = 2.823
- GRB 250402A: REM optical/NIR upper limits
- GRB 250402A: LCO optical counterpart detection
- GRB 250402A: refined SVOM/MXT data analysis
- GRB 250402A: SVOM/VT optical counterpart
- GRB 250402A: SVOM detection of a burst