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 251201B: SALT spectroscopic redshift z = 1.599
- GRB 251201B: Insight-HXMT/HE detection
- GRB 251201B: Fermi GBM Observation
- GRB 251201B: Kilonova-Catcher optical afterglow detection
- GRB 251201B: Swift/UVOT Detection
- GRB 251201B: GECAM-B observation of a long burst
- GRB 251201B: Swift-XRT refined Analysis
- GRB 251201B: SVOM/VT optical fading
- Swift GRB 251201B : MASTER optical counterpart detection
- GRB 251201B: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at Sutherland Observatory
- Swift GRB 251201B: Global MASTER-Net observations report
- GRB 251201B: Enhanced Swift-XRT position
- GRB 251201B: Swift detection of a burst with an optical counterpart
- GRB 251201B: Fermi GBM Final Real-time Localization