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 250430A: Leavitt Observatory optical upper limit
- GRB 250404A / EP250404a: Leavitt Observatory optical counterpart detection
- GRB 250317B: Leavitt Observatory optical upper limit
- GRB 250205A: Leavitt Observatory optical upper limit
- EP241217a : Leavitt Observatory optical upper limit
- GRB 240929A : Leavitt Observatory optical upper limit
- SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
- EP240801a: Leavitt Observatory optical observations
- GRB231111A: MDM 2.4m Hiltner Telescope Observation
- GRB 231111A: Leavitt Observatory optical observations
- Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
- GRB 230818A: Leavitt Observatory upper limit
- GRB 230812B: Leavitt Observatory optical observations
- GRB 230723B: Leavitt Observatory upper limit