Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

113 results found.

  1. IPN triangulation of GRB030101 (two large error boxes)
  2. Detection of activity from SGR 1900+14 with the RXTE/PCA
  3. RXTE Observations of SGR 1900+14
  4. The X-ray Flash 011030 ('GRB 011030')
  5. SGR 1900+14 : RXTE observations
  6. Further Optical Observations of GRB 010324
  7. Optical Observations of GRB 010324
  8. GCN resumes full operations
  9. Chandra observation of the X-ray afterglow of GRB991216
  10. GRB 990506, Optical Observations
  11. GRB 990506: Limits on the possible optical transient
  12. GRB990308 (Trig. 7457), optical observations
  13. GRB 980703: BATSE Observations

Advanced

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