Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. 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').

11 results found.

  1. GRB 230826A: Glowbug gamma-ray detection
  2. GRB 230826A: Swift-BAT refined analysis
  3. GRB 230826A: VZLUSAT-2 detection
  4. Subject: GRB230826A: Swift/UVOT upper limits
  5. GRB 230826A: GRBAlpha detection
  6. GRB 230826A: Fermi GBM Observation
  7. GRB 230826A: Enhanced Swift-XRT position
  8. GRB 230826A: Swift-XRT refined Analysis
  9. GRB 230826A: Mondy optical observations
  10. GRB 230826A: Swift detection of a burst
  11. GRB 230826A: Fermi GBM Final Real-time Localization


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