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"11 results found.
- GRB 251023B: Swift-UVOT Upper Limits
- GRB 251023B / EP251023b: Mondy optical upper limit
- GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
- GRB 251023B: OHP/T193 optical observations
- EP251023b/GRB 251023B: JinShan optical observation
- EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
- GRB 251023B: Glowbug gamma-ray detection
- GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
- GRB 251023B: CALET Gamma-Ray Burst Monitor detection
- EP#01709247298: Swift-XRT counterpart detection
- GRB 251023B / MAXI J0451+122: MAXI/GSC detection