Skip to main content
Updated Client Credential Expiration Policy. 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"
  1. GRB980326 optical observations
  2. GRB980326 optical observations
  3. GRB980326 optical observations
  4. GRB980326 optical observations
  5. GRB970508 SAO RAS optical observations
  6. Optical Observations of GRB 970508
  7. GRB 971214: Redshift from Keck Observations
  8. Near-IR follow-up on GRB 971227
  9. GRB971214: Keck R & I-band Observations
  10. GRB 971227: Optical Observations
  11. Optical Observations of the GRB 971227 field
  12. Optical Observations on GRB 971227
  13. GRB971227: Plaskett R-band observations
  14. GRB 971227: Optical clarifications
  15. Optical Observations for GRB 971227
  16. GRB971227: Further CAHA R-band images
  17. GRB971227: LOTIS observations
  18. GRB 971227: CAHA R-band images
  19. GRB 971227: Optical observations
  20. GRB971214: Optical Observations and Calibrations
  21. Sub-millimeter Observations of GRB 971214 at the JCMT
  22. GRB 971214: EUVE Observations
  23. GRB 971214: Redshift from Keck Optical Observations
  24. GRB 971214: Redshift from Keck Optical Observations
  25. GRB 971214: Apache Point Observatory Optical Observations
  26. GRB 971214: KPNO Optical Observations
  27. Optical Observations of GRB 971214 at Keck
  28. GRB 971214: Optical Observations
  29. Radio Observations of GRB 971214 at the VLA
  30. GRB 971214: USNOFS Observations Summary
  31. GRB 971024: KPNO Optical Observations Summary
  32. GRB 971024: Refined analysis by USNOFS Observations
  33. GRB 971024: KPNO Optical Observations
  34. GRB 971024: USNO Observations
  35. GRB 970925: BATSE Localization
  36. IRAS 18119-1342 and the possible new SGR
  37. Possible new SGR from US Naval Observatory
  38. RXTE Observations of SGR 1814-13
  39. GRB 970828: Palomar Observations
  40. GRB 970228: Keck/LRIS Optical Observations

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