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"17 results found.
- GRB 250103A: 1.6m Mephisto optical observations
- GRB 250103A: Swift-XRT afterglow detection
- GRB 250103A: Bassano Bresciano Observatory upper limit
- GRB 250103A: Swift-XRT observations
- GRB 250103A: NOT spectroscopic redshift
- GRB 250103A: Montarrenti Observatory optical detection
- GRB 250103A: Redshift 4.01 from OSIRIS+/GTC
- GRB 250103A: NOT optical observations
- GRB 250103A: TSHAO optical upper limit
- GRB 250103A: Fermi GBM Observation
- GRB 250103A: SVOM/VT optical counterpart confirmation
- GRB 250103A: Swift ToO observations
- GRB 250103A: Xinglong 2.16m Optical Candidate
- GRB 250103A: GOTO optical upper limit
- GRB 250103A: SVOM/C-GFT optical upper limit
- GRB 250103A: SVOM detection of a long burst (duplicate submission)
- GRB 250103A: SVOM detection of a long burst