Skip to main content
Announcing GCN Classic Migration Survey, End of Legacy Circulars Email. 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').

16 results found.

  1. GRB 201029A: Swift-XRT refined Analysis
  2. GRB 130925A: continuing Swift/XRT monitoring
  3. Konus-Wind observation of GRB 130925A
  4. GRB 121027A: sub-mm upper limit
  5. GRB 121027A: Swift/UVOT Possible Detection
  6. GRB 121027A: X-shooter redshift confirmation
  7. GRB 121027A - Gemini South spectroscopy
  8. GRB 121027A: GROND Confirmation of Rebrightening
  9. GRB 121027A: MASTER early prompt optical limit
  10. GRB 121027A: Swift-XRT refined Analysis
  11. GRB 121027A: Brightening IR counterpart
  12. GRB 121027A: Enhanced Swift-XRT position
  13. GRB 121027A: nIR afterglow candidate with AAT
  14. GRB 121027A: Swift-BAT refined analysis
  15. GRB 121027A: MAXI/GSC detection 40 minutes after the Swift Trigger
  16. GRB 121027A: Swift detection of a burst

Advanced

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