Skip to main content
New Swift-BAT/GUANO and IceCube Notice Types Available! 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 110903A: Suzaku WAM observation of the prompt emission
  2. GRB 110903A: Fermi GBM observation
  3. GRB 110903A: Swift/UVOT Upper Limits
  4. GRB 110903A: Swift-XRT observations
  5. Konus-Wind observation of GRB 110903A
  6. GRB 110903A: a long GRB detected by INTEGRAL


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