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 200925B: OSN Afterglow Candidate Discovery
- Fermi GRB 200906A: Global MASTER-Net observations report
- GRB 200906A: EMIR/GTC NIR upper limit
- GRB 200906A: LBT near-infrared upper limit
- GRB 200906A: Swift-BAT refined analysis
- GRB 200906A: Swift/UVOT Upper Limits
- GRB 200906A: GROWTH-India Telescope (GIT) optical r band upper limit
- GRB 200906A: OSN 1.5m Upper Limit
- GRB 200906A: Swift-XRT refined Analysis
- GRB 200906A: Fermi GBM detection
- GRB 200906A: Enhanced Swift-XRT position
- GRB 200906A: Nanshan/NEXT optical upper limit
- GRB 200906A: Swift detection of a burst
- GRB 200906A: Fermi GBM Final Real-time Localization