Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. 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').

15 results found.

  1. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  2. GRB 230205A: VLA radio afterglow confirmation
  3. GRB 230205A: Lowell Discovery Telescope Observations
  4. GRB 230205A: 6 GHz VLA observations
  5. GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
  6. GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
  7. GRB 230205A: Swift/UVOT Upper Limits
  8. GRB 230205A: LCOGT Optical Upper Limits
  9. GRB 230205A: SVOM/C-GFT optical upper limit
  10. GRB 230205A: OHP/T193 optical observations
  11. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  12. GRB 230205A: Swift-XRT refined Analysis
  13. GRB 230205A: Enhanced Swift-XRT position
  14. GRB 230205A: BOOTES-5/JGT early optical upper limit
  15. GRB 230205A: Swift detection of a burst


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