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"

16 results found.

  1. GRB 250225B: VLT host galaxy redshift z = 0.950
  2. GRB 250225B: GECAM-A detection
  3. GRB 250225B: Swift-BAT refined analysis
  4. GRB 250225B: VLT near-infrared afterglow confirmation
  5. GRB 250225B: EIRSAT-1 GMOD Detection
  6. GRB 250225B: VLT/HAWKI near-infrared observations
  7. GRB 250225B: VLT/Xshooter imaging
  8. GRB 250225B: INTEGRAL SPI-ACS detection
  9. GRB 250225B: Fermi GBM Observation
  10. GRB 250225B: REM NIR upper limits
  11. Konus-Wind detection of GRB 250225B
  12. GRB 250225B: VLT optical and near-infrared candidate counterpart
  13. GRB 250225B: VLT/FORS2 candidate optical afterglow
  14. GRB 250225B: SVOM/GRM observation of a long burst
  15. Swift GRB 250225B: Global MASTER-Net observations report
  16. GRB 250225B: Swift 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