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"4714 results found.
- GRB 990506 optical observations
- IPN localization for GRB990506
- GRB990321 REFINED IPN ANNULUS
- GRB990321 IPN TRIANGULATION
- ASM/IPN error box for GRB 990308 (BATSE #7457)
- GRB990123, Upcoming HST Service Observations
- GRB990123, optical observation
- GRB 981220 Optical observations
- GRB 981220:Optical Observations
- GRB981226 Optical Observation
- BeppoSAX NFI Observation of GRB980425
- GRB980326 X-ray Observations
- GRB980329 Keck K-band observations
- GRB980329 infrared observations