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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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').
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"

12 results found.

  1. GRB 250504A: EIRSAT-1 GMOD Detection
  2. GRB 250504A: Swift-BAT refined analysis
  3. GRB 250504A: Swift-XRT refined Analysis
  4. GRB 250504A: VLT/X-shooter upper limits
  5. GRB 250504A: SVOM/VT upper limit
  6. GRB 250504A: REM optical/NIR observations
  7. GRB 250504A: MeerLICHT optical afterglow detection
  8. GRB 250504A: Fermi GBM Observation
  9. GRB 250504A: Enhanced Swift-XRT position
  10. Fermi GRB 250504A: Global MASTER-Net observations report
  11. GRB 250504A: Swift detection of a burst
  12. GRB 250504A: Fermi GBM Final Real-time Localization

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

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