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').

19 results found.

  1. GRB 221028A: GRANDMA observations
  2. GRB 221028A: Detection by VZLUSAT-2
  3. GRB 221028A: Swift-XRT refined Analysis
  4. GRB 221028A: 1.3m DFOT Optical upper limit
  5. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  6. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  7. GRB 221028A: Correction to GCN 32893 - Fluence and flux are for 50-150 keV
  8. GRB 221028A: AKO Optical Upper Limit
  9. GRB 221028A, Swift-BAT refined analysis
  10. GRB 221028A: CrAO/ZTSh optical upper limit
  11. GRB 221028A: COATLI Upper Limits
  12. GRB 221028A: HCT optical upper limit
  13. GRB 221028A: AGILE detection
  14. GRB 221028A: MITSuME Okayama optical upper limits
  15. GRB 221028A: LCOGT Optical Upper Limits
  16. Swift GRB 221028A: Global MASTER-Net observations report
  17. GRB 221028A: BOOTES-4/MET optical upper limit
  18. GRB 221028A: GIT optical upper limit
  19. GRB 221028A: Swift detection of a burst


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