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"1109 results found.
- Transient EPW20240219aa: REM optical/NIR upper limits
- Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
- Transient EPW20240219aa: 7DT Optical Upper Limits
- VLA X-band observation of EPW20240219aa
- Transient EPW20240219aa: upper limit in gamma-ray range from SPI-ACS/INTEGRAL observations
- Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
- Fermi GBM Sub-Threshold Detection of EPW20240219aa as a likely GRB
- GRB 230307A: soft X-ray detection with LEIA
- GRB 221009A: LEIA X-ray Afterglow Detection