Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

10 results found.

  1. GRB 221027B: GRANDMA observations
  2. GRB 221027B: Swift-BAT refined analysis
  3. GRB 221027B: COATLI Upper Limits
  4. GRB 221027B: Swift/UVOT Upper Limits
  5. GRB 221027B: FRAM-ORM and Ondrejov SBT optical limits
  6. Swift GRB 221027B: Global MASTER-Net observations report
  7. GRB 221027B: Swift-XRT refined Analysis
  8. GRB 221027B: BOOTES-1 optical upper limit
  9. GRB 221027B: Enhanced Swift-XRT position
  10. GRB 221027B: 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