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"18 results found.
- GRB 250704B: Swift/UVOT Upper Limits
- GRB 250704B: Insight-HXMT detection
- EP250704a/GRB 250704B: GSP observations of the optical counterpart
- EP250704a/GRB 250704B: FTW optical and NIR observations of the counterpart
- Konus-Wind detection of short/hard GRB 250704B/ EP250704a
- EP250704a / GRB 250704B: NOT observations of the optical afterglow
- EP250704a/GRB 250704B VLT/HAWK-I NIR afterglow detection
- EP250704a / GRB 250704B: VLT/X-shooter spectroscopic redshift z = 0.661
- EP250704a / GRB 250704B: JinShan optical observations
- EP250704a / GRB 250704B: SAO RAS optical observations
- EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
- EP250704a / GRB 250704B: SVOM/VT optical blue counterpart
- EP250704a / GRB 250704B: Pan-STARRS iz-band imaging and photometry
- EP250704a / GRB250704B: Swift-XRT counterpart detection
- EP250704a / GRB 250704B - REM observations
- EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
- EP250704a: Einstein Probe detection of an X-ray transient
- GRB 250704B: SVOM/GRM observation of a short burst