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"12 results found.
- GRB 220921A: ATCA detection of radio counterpart
- GRB 220921A: LCOGT Optical Observations
- GRB 220921A: further MeerLICHT observations
- GRB 220921A: ALMA detection
- GRB 220921A: DDOTI Detection of the Afterglow
- Konus-Wind detection of GRB 220921A
- GRB 220921A: Fermi GBM detection
- GRB 220921A: MeerLICHT afterglow observations
- GRB 220921A: Swift-XRT Observations
- GRB 220921A: MASTER OT inside Fermi-LAT error-box
- GRB 220921A: Fermi-LAT detection
- GRB 220921A: Tiled Swift observations