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"16 results found.
- GRB 250225B: VLT host galaxy redshift z = 0.950
- GRB 250225B: GECAM-A detection
- GRB 250225B: Swift-BAT refined analysis
- GRB 250225B: VLT near-infrared afterglow confirmation
- GRB 250225B: EIRSAT-1 GMOD Detection
- GRB 250225B: VLT/HAWKI near-infrared observations
- GRB 250225B: VLT/Xshooter imaging
- GRB 250225B: INTEGRAL SPI-ACS detection
- GRB 250225B: Fermi GBM Observation
- GRB 250225B: REM NIR upper limits
- Konus-Wind detection of GRB 250225B
- GRB 250225B: VLT optical and near-infrared candidate counterpart
- GRB 250225B: VLT/FORS2 candidate optical afterglow
- GRB 250225B: SVOM/GRM observation of a long burst
- Swift GRB 250225B: Global MASTER-Net observations report
- GRB 250225B: Swift detection of a burst