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"6 results found.
- GW S240915b and S240919bn : Swift UVOT follow-up
- LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
- LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
- LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S240915b: Updated Sky localization and EM Bright Classification
- LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate