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"14 results found.
- GRB 250219A: NOT candidate host galaxy detection
- GRB 250219A: SVOM/C-GFT optical upper limit at early phase
- GRB 250219A: EP-FXT afterglow detection
- GRB 250219A: NUTTelA-TAO / BSTI Optical Limits
- GRB 250219A: GRANDMA/Kilonova-Catcher upper limits
- GRB 250219A: Swift/UVOT Upper Limits
- GRB 250219A: OHP/T193 optical upper limit
- GRB 250219A: NOT optical observations
- GRB 250219A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
- GRB 250219A: 1.6m Mephisto optical upper limits
- GRB 250219A: SVOM/VT optical counterpart
- GRB 250219A: Swift-XRT observations
- GRB 250219A: Swift ToO observations
- GRB 250219A: SVOM detection of a burst