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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 991208 optical observations
  2. Lowell/Perkins observation of GRB 991216
  3. GRB 991216 Optical Observation
  4. GRB 991208 Keck Spectroscopy
  5. GRB 991216: Extremely bright BATSE burst
  6. R-band Observations of GRB991208 at TNG
  7. GRB991208, optical observations
  8. GRB 991208 Keck Spectroscopy
  9. GRB991208 - millimeter detection
  10. GRB 991208, Optical Observation
  11. GRB991208 15-GHz observations
  12. GRB991208, optical observations
  13. GRB 991208 - OVRO detection
  14. GRB 991208 Optical Decay
  15. GRB 991208 optical observations
  16. GRB 991208 optical observations
  17. GRB 991208: Radio Observations
  18. IPN localization of GRB991208
  19. Optical Observations of GRB991105
  20. GRB991106: BeppoSAX/BATSE results
  21. GRB 991106, optical observations
  22. GRB991106, near-infrared observations
  23. BeppoSAX NFI Observation of GRB991106
  24. GRB 991106, radio observations
  25. GRB991106: the first BeppoSAX short GRB detection?
  26. GRB 991105: BATSE Observations
  27. IPN localization of GRB991105
  28. GRB 991106 Optical Observations
  29. GRB 991105, optical observations
  30. GRB991106, optical observation at SAO-RAS
  31. GRB 991106, LOTIS Optical Observations
  32. GRB 991106, optical observations
  33. BeppoSAX refined position for GRB991106
  34. BeppoSAX GRB Alert: GRB991106
  35. Revised BeppoSAX WFC position of GRB991105
  36. GRB991105: SAX-GRBM/-WFC detection
  37. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  38. GRB ALERT: GRB991105
  39. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  40. GRB 991014, Optical Observations
  41. GRB 991014 - BeppoSAX NFI observations
  42. GRB 991014, Optical Observations
  43. GRB 991014, radio observations
  44. GRB991014 BATSE Observations
  45. GRB 991014, Optical Observations
  46. GRB 991014, optical observations
  47. Super-LOTIS optical observation of GRB991014
  48. IPN/NFI error box for GRB991014
  49. IPN localization of GRB991014 - CORRECTION
  50. IPN localization of GRB991014
  51. BeppoSAX ALERT: GRB991014
  52. GRB 990915 optical observations
  53. GRB 990907 optical observations
  54. BATSE GRB trigger criteria
  55. Optical Observations of GRB990907
  56. IPN error box for GRB990915 (=BATSE 7766)
  57. IPN localization of BATSE #7766 (GRB990915)
  58. GRB990907: BeppoSAX follow up and X-ray afterglow
  59. GRB990907 and 990908
  60. IPN localization of GRB990907
  61. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  62. GRB990907: refined WFC position
  63. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  64. GRB 990712 Late Optical Decay and Host Galaxy
  65. GRB 990712, Optical Observation
  66. GRB990806 BeppoSAX follow up
  67. GRB990806: BATSE Observations
  68. GRB 990806 Optical observations
  69. Optical Observations of GRB990806
  70. GRB 990806, Optical Observations
  71. GRB 990806, optical observations
  72. GRB 990806, Optical Observations
  73. GRB990806 UBVRIJHK observations
  74. GRB990806: possible X-ray afterglow, BeppoSAX
  75. BeppoSAX ALERT GRB990806: Summer GRB
  76. GRB 990712 Optical Observations
  77. GRB990705: No Evidence for Neutrino Signal
  78. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  79. VLT spectrum of GRB990712
  80. GRB 990712
  81. Late-time HST/STIS Observations of GRB 990510
  82. Refined BeppoSAX-WFC position of GRB990712
  83. BeppoSAX NFI Observation of GRB990705
  84. BeppoSAX NFI Observation of GRB990705
  85. Updated Astrometry for the IR Counterpart of GRB990705
  86. GRB 990705, R-band observations
  87. Updated IPN localization of GRB990705
  88. IPN localization of GRB990704
  89. IPN localization of GRB990705
  90. Infrared and Optical Observations of GRB990705
  91. GRB 990705, radio observations
  92. GRB990704: SAX-NFI results summary
  93. GRB990704 radio and optical observations
  94. BeppoSAX GRB990705: possible X-ray afterglow
  95. GRB 990704 X-ray Observations
  96. GRB 990704 Optical Observations
  97. GRB 990704, optical observations
  98. GRB990704
  99. GRB990705: Intriguing Positional Coincidences
  100. GRB990704

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