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"13 results found.
- EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
- GRB 240930B: SVOM/C-GFT optical upper limit
- GRB 240930B / EP 240930a: SVOM/GRM observation
- IPN triangulation of GRB 240930B / EP 240930a
- GRB 240930B: CALET Gamma-Ray Burst Monitor detection
- GRB 240930B: Fermi GBM Observation
- GRB 240930B: GRBAlpha detection
- GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
- EP240930a: EP-FXT follow-up observation update
- EP240930a: GOTO optical upper limits
- EP240930a: EP-WXT detection of a fast X-ray transient
- Fermi GRB 240930B: Global MASTER-Net observations report
- GRB 240930B: Fermi GBM Final Real-time Localization