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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. GRB 991014, Optical Observations
  2. GRB 991014, radio observations
  3. GRB991014 BATSE Observations
  4. GRB 991014, Optical Observations
  5. GRB 991014, optical observations
  6. Super-LOTIS optical observation of GRB991014
  7. IPN/NFI error box for GRB991014
  8. IPN localization of GRB991014 - CORRECTION
  9. IPN localization of GRB991014
  10. BeppoSAX ALERT: GRB991014
  11. GRB 990915 optical observations
  12. GRB 990907 optical observations
  13. BATSE GRB trigger criteria
  14. Optical Observations of GRB990907
  15. IPN error box for GRB990915 (=BATSE 7766)
  16. IPN localization of BATSE #7766 (GRB990915)
  17. GRB990907: BeppoSAX follow up and X-ray afterglow
  18. GRB990907 and 990908
  19. IPN localization of GRB990907
  20. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  21. GRB990907: refined WFC position
  22. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  23. GRB 990712 Late Optical Decay and Host Galaxy
  24. GRB 990712, Optical Observation
  25. GRB990806 BeppoSAX follow up
  26. GRB990806: BATSE Observations
  27. GRB 990806 Optical observations
  28. Optical Observations of GRB990806
  29. GRB 990806, Optical Observations
  30. GRB 990806, optical observations
  31. GRB 990806, Optical Observations
  32. GRB990806 UBVRIJHK observations
  33. GRB990806: possible X-ray afterglow, BeppoSAX
  34. BeppoSAX ALERT GRB990806: Summer GRB
  35. GRB 990712 Optical Observations
  36. GRB990705: No Evidence for Neutrino Signal
  37. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  38. VLT spectrum of GRB990712
  39. GRB 990712
  40. Late-time HST/STIS Observations of GRB 990510
  41. Refined BeppoSAX-WFC position of GRB990712
  42. BeppoSAX NFI Observation of GRB990705
  43. BeppoSAX NFI Observation of GRB990705
  44. Updated Astrometry for the IR Counterpart of GRB990705
  45. GRB 990705, R-band observations
  46. Updated IPN localization of GRB990705
  47. IPN localization of GRB990704
  48. IPN localization of GRB990705
  49. Infrared and Optical Observations of GRB990705
  50. GRB 990705, radio observations
  51. GRB990704: SAX-NFI results summary
  52. GRB990704 radio and optical observations
  53. BeppoSAX GRB990705: possible X-ray afterglow
  54. GRB 990704 X-ray Observations
  55. GRB 990704 Optical Observations
  56. GRB 990704, optical observations
  57. GRB990704
  58. GRB990705: Intriguing Positional Coincidences
  59. GRB990704
  60. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  61. GRB990704, optical observations
  62. GRB990704: possible X-ray afterglow
  63. Identification of a possible optical counterpart for GRB990704
  64. GRB990704
  65. Refined BeppoSAX-WFC position of GRB990704
  66. GRB990704: BeppoSAX detection
  67. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  68. Optical Observations of GRB990627
  69. GRB 990627, radio observations
  70. GRB990627: BeppoSAX-WFC final location
  71. BeppoSAX: GRB990625
  72. Late-time HST/STIS Observation of GRB 990123
  73. GRB 990506 - clarification to GCN 352
  74. GRB 990506 - Optical Observations
  75. Optical Observations of GRB 990506
  76. GRB 990506 Radio Transient
  77. GRB990527 Optical Observations
  78. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  79. IPN error box for GRB990527
  80. Late Afterglows of GRBs 990510, 990123
  81. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  82. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  83. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  84. GRB 990506 optical observation
  85. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  86. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  87. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  88. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  89. radio observations of X-ray/GRB transient field
  90. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  91. Optical report on X-ray/GRB transient
  92. radio detection of X-ray/GRB transient
  93. BeppoSAX: A new fast X-ray transient
  94. GRB 990510: optical observations
  95. GRB990510: photometric and spectroscopic observations with the VLT
  96. GRB 990510: optical linear polarization
  97. GRB 990510: optical observations
  98. GRB990510, VI observations
  99. GRB 990506 R band observations
  100. GRB990510: X-ray afterglow

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