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"3113 results found.
- GRB 990704, optical observations
- GRB 990506, optical observations from +1 to +3 hours
- GRB 990123: BVRI standards in the field
- GRB990123 Optical Observations
- GRB990123, early optical counterpart detection
- GRB990123, BeppoSAX WFC detection and NFI planned follow-up
- GRB981226, BeppoSAX Christmas GRB
- GRB981220 I-band Observations
- BATSE on-board GRB trigger change
- GRB980326 IPN annulus
- GRB980329 IPN annulus
- GRB 971024: Refined analysis by USNOFS Observations
- GRB 971024: USNO Observations