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"13 results found.
- FRB 250316A: NOT optical upper limit for the X ray source EP J120944.2+585060
- FRB 250316A: COLIBRÍ/DDRAGO Optical follow up of the X ray source EP J120944.2+585060
- FRB 250316A: DDOTI Continued Optical Observations (Third Epoch)
- FRB 250316A: DDOTI Continued Optical Observations
- GRB 250316A: Swift/UVOT Upper Limits
- GRB 250316A: AbAO AS-32 Optical Upper Limit
- GRB 250316A: Swift-XRT afterglow detection
- GRB 250316A: Fermi GBM Observation
- GRB 250316A: Swift-XRT observations
- Fermi GRB 250316A: Global MASTER-Net observations report
- GRB 250316A: Swift ToO observations
- GRB 250316A: Swift/BAT-GUANO arcminute localization of a burst
- GRB 250316A: Fermi GBM Final Real-time Localization