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"19 results found.
- GRB 250924A: SVOM/GRM observation
- GRB 250924A: Swift-BAT refined analysis
- GRB 250924A: 1.6m Mephisto optical upper limits
- GRB 250924A: SAO RAS optical observations
- GRB 250924A: NOT optical observations
- GRB 250924A: AstroSat CZTI detection
- GRB 250924A: SVOM/VT optical observation
- GRB 250924A: Swift/UVOT Detection
- GRB 250924A: Swift-XRT refined Analysis
- GRB 250924A: Enhanced Swift-XRT position
- GRB 250924A: J-band detection with WINTER
- GRB 250924A: GROWTH-India Telescope Upper Limits
- GRB 250924A: KAIT optical observations
- GRB 250924A: Mondy optical observations, afterglow fading
- GRB 250924A: Kilonova-Catcher optical afterglow detection
- GRB 250924A: COLIBRÍ optical observations
- Swift GRB 250924A: Global MASTER-Net observations report
- GRB 250924A: DDOTI Detection of the Optical Counterpart
- GRB 250924A: Swift detection of a burst with an optical counterpart