Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

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').

12 results found.

  1. GRB 231129A: VZLUSAT-2 detection
  2. GRB 231129A : MITSuME Akeno optical upper limits
  3. GRB 231129A: Swift-BAT refined analysis
  4. GRB 231129A: BOOTES-5/JGT optical upper limit
  5. GRB 231129A: JinShan optical upper limit
  6. GRB 231129A: Swift/UVOT Upper Limits
  7. GRB 231129A: optical upper limit in Mondy observatory
  8. GRB 231129A: Enhanced Swift-XRT position
  9. GRB 231129A: Swift-XRT refined Analysis
  10. GRB 231129A: GECAM-C detection of a long burst
  11. GRB 231129A: INTEGRAL detection of a long GRB
  12. GRB 231129A: Swift detection of a burst


Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit