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').

12 results found.

  1. GRB 210411C: A very significant early X-ray afterglow
  2. GRB 210411C: Swift/UVOT Detection
  3. GRB 210411C: Swift-BAT refined analysis
  4. GRB 210411C: Chilescope optical observations
  5. GRB 210411C: ePESSTO+ NTT optical observations
  6. GRB 210411C: Swift-XRT refined Analysis
  7. GRB 210411C: VLT/X-shooter redshift
  8. Swift GRB 210411C: Global MASTER-Net observations report
  9. GRB 210411C: BOOTES-4/MET optical upper limit
  10. GRB 210411C: LCO Optical Afterglow Candidate
  11. GRB 210411C: Enhanced Swift-XRT position
  12. GRB 210411C: Swift detection of a burst with an optical counterpart

Advanced

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