Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

5157 results found.

  1. GRB991208, optical observations
  2. GRB 991106, optical observations
  3. GRB991106, near-infrared observations
  4. GRB 991106, radio observations
  5. GRB 991014 - BeppoSAX NFI observations
  6. IPN localization of GRB990907
  7. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  8. GRB 990712, Optical Observation
  9. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  10. GRB 990712
  11. BeppoSAX: GRB990625
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. GRB990506 observation plan
  14. Refined IPN error box for GRB990506
  15. GRB 990506, armchair astronomy
  16. ASM/IPN error box for GRB 990308 (BATSE #7457)
  17. GRB990308 (Trig. 7457), optical observations
  18. Optical Observations of GRB990217
  19. GRB990123 observations
  20. GRB 990123: Reduced HST Images
  21. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  22. GRB 990123: New Constraints on Possible Foreground Galaxies
  23. GRB990123 Optical Observations
  24. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  25. GRB 990123: Continued Radio Observations
  26. Search for Potential Images of GRB 990123
  27. GRB990123, Optical BVRI Observations
  28. GRB 990123: near-infrared observations.
  29. GRB990123: NIR Observation
  30. "GRB 990123: New BV Observations"
  31. GRB990123 Optical Observations
  32. GRB981220
  33. GRB 981220 Optical observations
  34. GRB 981220 and GRB 981226, optical observations
  35. GRB 981226 optical observations
  36. GRB981220 B, R and I band observations
  37. GRB 981226 - Infrared Observations
  38. GRB 981220
  39. GRB981220 I-band Observations
  40. GRB980425 Optical Follow-up
  41. GRB980613 Optical Observations
  42. SGR 1627-41
  43. GRB980519 optical observations
  44. GRB 980519 Optical Observations
  45. GRB 980425 Brightness Temperature
  46. GRB980329, Fading IR counterpart to radio source
  47. Near-IR follow-up on GRB 971227
  48. GRB971214: Keck R & I-band Observations
  49. Optical Observations of the GRB 971227 field
  50. GRB971227: Plaskett R-band observations
  51. GRB971227: Further CAHA R-band images
  52. GRB 971214: KPNO Optical Observations
  53. Optical Observations of GRB 971214 at Keck
  54. GRB 971214: Optical Observations
  55. GRB 971024: Refined analysis by USNOFS Observations
  56. GRB 971024: USNO Observations
  57. GRB 970228: Keck/LRIS Optical Observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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