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 251222A: NUTTelA-TAO Early Measurements
- EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
- GRB 251126A NUTTelA-TAO Early Measurements
- EP251023a: Assy AZT-20 optical observations
- GRB 251013C NUTTelA-TAO / BSTI Early Measurements
- EP250901a: Mondy, Assy and SAO RAS optical limits
- EP250711a: CrAO and Assy optical observations
- GRB 250617B: Assy AZT-20 Optical Observations
- GRB 250617B: NUTTelA-TAO early time optical observations
- GRB 250430A: NUTTelA-TAO Early Measurements
- GRB 250402A: NUTTelA-TAO Early Optical Limits
- EP250302a: NUTTelA-TAO Early Measurments
- GRB 250221A: continued Assy optical observations, brightening afterglow confirmation
- GRB 250221A: Assy optical observations
- GRB 250219A: NUTTelA-TAO / BSTI Optical Limits
- GRB 250101A: NUTTelA-TAO / BSTI Optical Limits
- GRB 250101A NUTTelA-TAO / BSTI Early Measurements