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"13 results found.
- GRB070621: RTT150 optical observations
- GRB 070621: VLT optical observations
- GRB 070621: Swift/UVOT Upper Limits
- Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
- GRB 070621: Swift-BAT refined analysis
- GRB 070621: Gemini South optical imaging
- GRB 070621: UVOT-enhanced XRT position
- GRB 070621: NOT observations
- GRB070621: OPTIMA-Burst optical upper limit
- GRB 070621: TAROT Calern observatory optical observations
- GRB 070621: Watcher Observations
- GRB 070621: ROTSE-III Prompt Optical Limits
- GRB 070621: Swift detection of a burst