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').

10043 results found.

  1. GRB990510 optical observations
  2. GRB 990510 optical observations
  3. GRB990510: NFI X-ray source
  4. GRB 990506 optical observations
  5. GRB 990316, Optical observations
  6. GRB990217: BeppoSAX/GRBM data
  7. Optical Observations of GRB990217
  8. GRB 990123: Discovery of the Probable Host Galaxy
  9. GRB 990123: New Constraints on Possible Foreground Galaxies
  10. GRB990123, Optical BVRI Observations
  11. GRB990123, ASCA X-ray observation of afterglow
  12. GRB 990123 Spectroscopic Redshifts
  13. GRB 990123 Optical Follow-Up
  14. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  15. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  16. GRB981220, Correction to GCN 179
  17. GRB981220 B, R and I band observations
  18. GRB 981220 optical R and I observations
  19. GRB 981226 - Infrared Observations
  20. GRB 981226 optical observations
  21. BeppoSAX NFI Observation of GRB980425
  22. GRB980425 Optical Follow-up
  23. GRB980703: LOTIS observation at early times
  24. GRB 980703
  25. GRB980703
  26. GRB980703 optical followup
  27. SGR1627-41, BeppoSAX-GRBM detections
  28. GRB980613, BeppoSAX WFC positions
  29. GRB980519, BeppoSAX-WFC updated position
  30. GRB980519, BeppoSAX-WFC position
  31. BSAX Observations of GRB980425 field
  32. GRB 980425 optical observations
  33. GRB 980425 optical observations
  34. GRB 980425 optical observations
  35. GRB980329 optical observations
  36. GRB971214: Keck R & I-band Observations
  37. Optical Observations of the GRB 971227 field
  38. Optical Observations on GRB 971227
  39. GRB971227: Plaskett R-band observations
  40. GRB 971227: Optical clarifications
  41. GRB971227: LOTIS observations
  42. GRB 971214: KPNO Optical Observations
  43. Optical Observations of GRB 971214 at Keck

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