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').

6 results found.

  1. GRB 170912A: Swift-BAT refined analysis
  2. GRB 170912A: Swift-XRT refined Analysis
  3. GRB 170912A: Swift/UVOT Upper-Limits
  4. GRB 170912A: Enhanced Swift-XRT position
  5. GRB 170912A: Prompt enhanced Swift-XRT position
  6. GRB 170912A: 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