Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

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"

10 results found.

  1. GRB 250530A: VLT/X-shooter host galaxy redshift z = 1.486
  2. GRB 250530A: SVOM/GRM analysis
  3. GRB 250530A: VLT/HAWK-I NIR counterpart fading
  4. GRB 250530A: TNG detection of a NIR source inside the Swift/XRT error circle
  5. GRB 250530A: EP-FXT counterpart detection
  6. GRB 250530A: SVOM/VT optical upper limit
  7. GRB 250530A: Swift-XRT counterpart detection
  8. GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate retraction and detection limit
  9. GRB 250530A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  10. GRB 250530A: SVOM detection of a burst

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

Looking for U.S. government information and services? Visit USA.gov