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. GRB100504A: Optical upper limits at IAO
  2. GRB 100504A: Fermi GBM observation
  3. GRB 100504A: Swift/UVOT Observations
  4. GRB 100504A: Swift-XRT refined analysis
  5. GRB 100504A: Enhanced Swift-XRT position
  6. GRB 100504A: GROND Upper limits
  7. GRB 100504A: Swift-BAT refined analysis
  8. GRB 100504A: SARA-South Upper Limit
  9. GRB 100504A: UVOT-enhanced XRT position
  10. GRB 100504A: 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