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.
- LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
- LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
- LIGO/Virgo/KAGRA S230731an: not observable by Fermi-GBM
- LIGO/Virgo/KAGRA S230731an: Updated Sky Localization and EM Bright Classification, and Correction to Source Classification
- LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S230731an: Identification of a GW compact binary merger candidate