Skip to main content
GCN at AAS 245, Legacy Circulars Address Retirement. 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. GRB990806: BATSE Observations
  2. GRB 990806 Optical observations
  3. Optical Observations of GRB990806
  4. GRB 990806, Optical Observations
  5. GRB 990806, optical observations
  6. GRB 990806, Optical Observations
  7. GRB990806 UBVRIJHK observations
  8. GRB990806: possible X-ray afterglow, BeppoSAX
  9. BeppoSAX ALERT GRB990806: Summer GRB
  10. GRB 990712 Optical Observations
  11. GRB990705: No Evidence for Neutrino Signal
  12. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  13. VLT spectrum of GRB990712
  14. GRB 990712
  15. Late-time HST/STIS Observations of GRB 990510
  16. Refined BeppoSAX-WFC position of GRB990712
  17. BeppoSAX NFI Observation of GRB990705
  18. BeppoSAX NFI Observation of GRB990705
  19. Updated Astrometry for the IR Counterpart of GRB990705
  20. GRB 990705, R-band observations
  21. Updated IPN localization of GRB990705
  22. IPN localization of GRB990704
  23. IPN localization of GRB990705
  24. Infrared and Optical Observations of GRB990705
  25. GRB 990705, radio observations
  26. GRB990704: SAX-NFI results summary
  27. GRB990704 radio and optical observations
  28. BeppoSAX GRB990705: possible X-ray afterglow
  29. GRB 990704 X-ray Observations
  30. GRB 990704 Optical Observations
  31. GRB 990704, optical observations
  32. GRB990704
  33. GRB990705: Intriguing Positional Coincidences
  34. GRB990704
  35. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  36. GRB990704, optical observations
  37. GRB990704: possible X-ray afterglow
  38. Identification of a possible optical counterpart for GRB990704
  39. GRB990704
  40. Refined BeppoSAX-WFC position of GRB990704
  41. GRB990704: BeppoSAX detection
  42. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  43. Optical Observations of GRB990627
  44. GRB 990627, radio observations
  45. GRB990627: BeppoSAX-WFC final location
  46. BeppoSAX: GRB990625
  47. Late-time HST/STIS Observation of GRB 990123
  48. GRB 990506 - clarification to GCN 352
  49. GRB 990506 - Optical Observations
  50. Optical Observations of GRB 990506
  51. GRB 990506 Radio Transient
  52. GRB990527 Optical Observations
  53. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  54. IPN error box for GRB990527
  55. Late Afterglows of GRBs 990510, 990123
  56. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  57. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  58. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  59. GRB 990506 optical observation
  60. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  61. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  62. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  63. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  64. radio observations of X-ray/GRB transient field
  65. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  66. Optical report on X-ray/GRB transient
  67. radio detection of X-ray/GRB transient
  68. BeppoSAX: A new fast X-ray transient
  69. GRB 990510: optical observations
  70. GRB990510: photometric and spectroscopic observations with the VLT
  71. GRB 990510: optical linear polarization
  72. GRB 990510: optical observations
  73. GRB990510, VI observations
  74. GRB 990506 R band observations
  75. GRB990510: X-ray afterglow
  76. GRB 990510: optical observation
  77. VLT spectrum of GRB990510
  78. GRB 990510: Broad Band Break
  79. GRB 990510: BATSE Observations
  80. GRB990510: optical observation
  81. GRB 990510 Optical Observations
  82. GRB 990510, BVI photometry
  83. GRB 990510 optical observations
  84. GRB 990510: BeppoSAX/GRBM observations
  85. GRB990510 optical observations
  86. GRB990510
  87. GRB 990510 optical observations
  88. GRB 990510 optical observations
  89. Galactic extinction towards GRB 990510
  90. GRB990510: NFI X-ray source
  91. GRB 990510 optical observations
  92. IPN localization of GRB990510
  93. GRB 990506 Radio Observations
  94. GRB 990123, optical monitoring
  95. GRB 990506: BATSE Observations
  96. GRB 990506, optical observations
  97. GRB 990510: Final BeppoSAX-WFC Coordinates
  98. GRB 990506, Optical Observations
  99. GRB 990506 optical observations
  100. GRB 990506 optical observations

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov