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').

9 results found.

  1. GRB 200509A: Swift-BAT refined analysis
  2. GRB 200509A: GROWTH-India r band upper limits
  3. GRB 200509A: Swift/UVOT Detection
  4. Swift GRB 200509A: Global MASTER-Net observations report
  5. GRB 200509A: LCO Optical Afterglow Detection
  6. GRB 200509A: Swift-XRT refined Analysis
  7. GRB 200509A: Enhanced Swift-XRT position
  8. GRB 200509A: Zadko observatory - Gingin optical upper limits
  9. GRB 200509A: Swift detection of a burst with a possible optical counterpart

Advanced

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