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').
  1. IPN localization of GRB991208
  2. Optical Observations of GRB991105
  3. GRB991106: BeppoSAX/BATSE results
  4. GRB 991106, optical observations
  5. GRB991106, near-infrared observations
  6. BeppoSAX NFI Observation of GRB991106
  7. GRB 991106, radio observations
  8. GRB991106: the first BeppoSAX short GRB detection?
  9. GRB 991105: BATSE Observations
  10. IPN localization of GRB991105
  11. GRB 991106 Optical Observations
  12. GRB 991105, optical observations
  13. GRB991106, optical observation at SAO-RAS
  14. GRB 991106, LOTIS Optical Observations
  15. GRB 991106, optical observations
  16. BeppoSAX refined position for GRB991106
  17. BeppoSAX GRB Alert: GRB991106
  18. Revised BeppoSAX WFC position of GRB991105
  19. GRB991105: SAX-GRBM/-WFC detection
  20. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  21. GRB ALERT: GRB991105
  22. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  23. GRB 991014, Optical Observations
  24. GRB 991014 - BeppoSAX NFI observations
  25. GRB 991014, Optical Observations
  26. GRB 991014, radio observations
  27. GRB991014 BATSE Observations
  28. GRB 991014, Optical Observations
  29. GRB 991014, optical observations
  30. Super-LOTIS optical observation of GRB991014
  31. IPN/NFI error box for GRB991014
  32. IPN localization of GRB991014 - CORRECTION
  33. IPN localization of GRB991014
  34. BeppoSAX ALERT: GRB991014
  35. GRB 990915 optical observations
  36. GRB 990907 optical observations
  37. BATSE GRB trigger criteria
  38. Optical Observations of GRB990907
  39. IPN error box for GRB990915 (=BATSE 7766)
  40. IPN localization of BATSE #7766 (GRB990915)
  41. GRB990907: BeppoSAX follow up and X-ray afterglow
  42. GRB990907 and 990908
  43. IPN localization of GRB990907
  44. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  45. GRB990907: refined WFC position
  46. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  47. GRB 990712 Late Optical Decay and Host Galaxy
  48. GRB 990712, Optical Observation
  49. GRB990806 BeppoSAX follow up
  50. GRB990806: BATSE Observations
  51. GRB 990806 Optical observations
  52. Optical Observations of GRB990806
  53. GRB 990806, Optical Observations
  54. GRB 990806, optical observations
  55. GRB 990806, Optical Observations
  56. GRB990806 UBVRIJHK observations
  57. GRB990806: possible X-ray afterglow, BeppoSAX
  58. BeppoSAX ALERT GRB990806: Summer GRB
  59. GRB 990712 Optical Observations
  60. GRB990705: No Evidence for Neutrino Signal
  61. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  62. VLT spectrum of GRB990712
  63. GRB 990712
  64. Late-time HST/STIS Observations of GRB 990510
  65. Refined BeppoSAX-WFC position of GRB990712
  66. BeppoSAX NFI Observation of GRB990705
  67. BeppoSAX NFI Observation of GRB990705
  68. Updated Astrometry for the IR Counterpart of GRB990705
  69. GRB 990705, R-band observations
  70. Updated IPN localization of GRB990705
  71. IPN localization of GRB990704
  72. IPN localization of GRB990705
  73. Infrared and Optical Observations of GRB990705
  74. GRB 990705, radio observations
  75. GRB990704: SAX-NFI results summary
  76. GRB990704 radio and optical observations
  77. BeppoSAX GRB990705: possible X-ray afterglow
  78. GRB 990704 X-ray Observations
  79. GRB 990704 Optical Observations
  80. GRB 990704, optical observations
  81. GRB990704
  82. GRB990705: Intriguing Positional Coincidences
  83. GRB990704
  84. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  85. GRB990704, optical observations
  86. GRB990704: possible X-ray afterglow
  87. Identification of a possible optical counterpart for GRB990704
  88. GRB990704
  89. Refined BeppoSAX-WFC position of GRB990704
  90. GRB990704: BeppoSAX detection
  91. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  92. Optical Observations of GRB990627
  93. GRB 990627, radio observations
  94. GRB990627: BeppoSAX-WFC final location
  95. BeppoSAX: GRB990625
  96. Late-time HST/STIS Observation of GRB 990123
  97. GRB 990506 - clarification to GCN 352
  98. GRB 990506 - Optical Observations
  99. Optical Observations of GRB 990506
  100. GRB 990506 Radio Transient

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