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"14 results found.
- GRB 240821A: further radio observations with the VLA
- GRB 240821A: Keck/LRIS spectroscopic observations
- GRB 240821A: Host galaxy redshift from VLT/X-shooter
- GRB 240821A: radio observation with the VLA
- SVOM GRB 240821A: optical afterglow discovery
- GRB 240821A: Swift/UVOT observations of the XRT sources.
- GRB 240821A: Swift-XRT observations
- GRB 240821A: JinShan optical upper limits
- GRB 240821A: GMG Optical Upper Limit
- Fermi GRB 240821A: Global MASTER-Net observations report
- GRB 240821A: Fermi GBM Observation
- GRB 240821A: EP-FXT follow-up observation and afterglow candidates
- GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
- GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)