Skip to main content
Circulars over Kafka event name backfill. 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.

Lucene Examples (click to copy):

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

32 results found.

  1. Comparison of ICSP VLF observation of GRB 090424 with satellite observations
  2. GRB 090424: WSRT Radio Observations
  3. GMRT observation of GRB 090424 afterglow
  4. GRB 090423: optical limit
  5. GRB 090424: optical observations
  6. GRB 090424, SMARTS optical/IR afterglow monitoring
  7. GRB 090424: YNAO-GMG observations
  8. GRB 090424 : Multiband Optical observation from Nainital
  9. GRB 090424: Continued R-band monitoring
  10. GRB 090424: Suzaku WAM observation of the prompt emission
  11. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  12. Detection of bright radio afterglow of GRB 090424 with the VLA
  13. GRB 090424: MASTER-Net prompt optical limit
  14. GRB 090424: WHT ISIS spectroscopy
  15. GRB 090424 : Lulin 1m telescope optical observations
  16. GRB 090424: THO optical observations
  17. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  18. GRB 090424 Gemini-South Redshift
  19. GRB 090424 : TAOS optical detection
  20. GRB 090424 optical observations
  21. GRB 090424: Liverpool Telescope observations
  22. GRB 090424: Swift-XRT refined analysis
  23. GRB 090424: Optical observations from 1.23m CAHA
  24. Swift/UVOT observations of GRB 090424
  25. GRB 090424: MASTER-Net prompt optical observations
  26. GRB 090424: Enhanced Swift-XRT position
  27. GRB 090424: Swift-BAT refined analysis
  28. GRB 090424: Fermi GBM Observation
  29. GRB 090424: SDSS Galaxy at the Swift position
  30. GRB 090424: TNT optical observations
  31. GRB 090424: ROTSE-III Confimation of Optical Counterpart
  32. GRB 090424: Swift detection of a burst with an optical counterpart

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov