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"20 results found.
- GRB 250725A: AstroSat CZTI detection
- GRB 250725A: PRIME near-infrared observations
- GRB 250725A: Swift-XRT refined Analysis
- GRB 250725A: Fermi GBM Observation
- GRB 250725A: Swift-BAT refined analysis
- Konus-Wind detection of GRB 250725A
- GRB 250725A: SVOM/GRM observation
- GRB 250725A: Global MASTER-Net: First Optical Synchronous Observatios of Short GRB.
- GRB 250725A: Swift/UVOT Upper Limits
- GRB 250725A: Fermi-LAT detection
- GRB 250725A: VLT/FORS2 spectroscopic redshift z = 5.26
- GRB 250725A: BOOTES-7 early optical detection
- GRB 250725A: SVOM/VT optical candidate
- GRB 250725A: MASTER-OAFA optical detection of very fast afterglow
- GRB 250725A: Enhanced Swift-XRT position
- GRB 250725A: Swift detection of a burst
- Swift GRB 250725A: Global MASTER-Net OT detection
- GRB 250725A: Fermi GBM Final Real-time Localization
- Fermi GRB 250725A: Global MASTER-Net observations report
- Swift GRB 250725A: Global MASTER-Net observations report