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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. Lowell/Perkins observation of GRB 991216
  2. GRB991216, optical observations
  3. GRB991216 Optical and infrared observations of Beethoven Burst
  4. Refined IPN localization of GRB991216
  5. GRB 991216 Radio Observations
  6. GRB 991217
  7. GRB 991208 Keck Spectroscopy
  8. GRB 991208 Infrared Detection
  9. GRB991216
  10. GRB 991216--Summary of RXTE Observations
  11. GRB 991216 Optical Observations
  12. GRB 991216, optical observations
  13. GRB 991208 SAO-RAS Spectroscopy
  14. SAX J2303.2+0015: an x-ray/GRB?
  15. GRB 991216, Optical Transient
  16. GRB 991216, Optical Afterglow
  17. GRB991216 ('Beethoven Burst') B, R, and K Observations
  18. GRB 991216: Comparison with DPOSS images
  19. GRB991216, infrared observations
  20. GRB991216 Optical Observations
  21. GRB 991208 optical observations
  22. Lowell/Perkins observation of GRB 991216
  23. GRB 991216 Optical Observation
  24. GRB 991208 Keck Spectroscopy
  25. GRB 991216: Extremely bright BATSE burst
  26. R-band Observations of GRB991208 at TNG
  27. GRB991208, optical observations
  28. GRB 991208 Keck Spectroscopy
  29. GRB991208 - millimeter detection
  30. GRB 991208, Optical Observation
  31. GRB991208 15-GHz observations
  32. GRB991208, optical observations
  33. GRB 991208 - OVRO detection
  34. GRB 991208 Optical Decay
  35. GRB 991208 optical observations
  36. GRB 991208 optical observations
  37. GRB 991208: Radio Observations
  38. IPN localization of GRB991208
  39. Optical Observations of GRB991105
  40. GRB991106: BeppoSAX/BATSE results
  41. GRB 991106, optical observations
  42. GRB991106, near-infrared observations
  43. BeppoSAX NFI Observation of GRB991106
  44. GRB 991106, radio observations
  45. GRB991106: the first BeppoSAX short GRB detection?
  46. GRB 991105: BATSE Observations
  47. IPN localization of GRB991105
  48. GRB 991106 Optical Observations
  49. GRB 991105, optical observations
  50. GRB991106, optical observation at SAO-RAS
  51. GRB 991106, LOTIS Optical Observations
  52. GRB 991106, optical observations
  53. BeppoSAX refined position for GRB991106
  54. BeppoSAX GRB Alert: GRB991106
  55. Revised BeppoSAX WFC position of GRB991105
  56. GRB991105: SAX-GRBM/-WFC detection
  57. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  58. GRB ALERT: GRB991105
  59. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  60. GRB 991014, Optical Observations
  61. GRB 991014 - BeppoSAX NFI observations
  62. GRB 991014, Optical Observations
  63. GRB 991014, radio observations
  64. GRB991014 BATSE Observations
  65. GRB 991014, Optical Observations
  66. GRB 991014, optical observations
  67. Super-LOTIS optical observation of GRB991014
  68. IPN/NFI error box for GRB991014
  69. IPN localization of GRB991014 - CORRECTION
  70. IPN localization of GRB991014
  71. BeppoSAX ALERT: GRB991014
  72. GRB 990915 optical observations
  73. GRB 990907 optical observations
  74. BATSE GRB trigger criteria
  75. Optical Observations of GRB990907
  76. IPN error box for GRB990915 (=BATSE 7766)
  77. IPN localization of BATSE #7766 (GRB990915)
  78. GRB990907: BeppoSAX follow up and X-ray afterglow
  79. GRB990907 and 990908
  80. IPN localization of GRB990907
  81. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  82. GRB990907: refined WFC position
  83. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  84. GRB 990712 Late Optical Decay and Host Galaxy
  85. GRB 990712, Optical Observation
  86. GRB990806 BeppoSAX follow up
  87. GRB990806: BATSE Observations
  88. GRB 990806 Optical observations
  89. Optical Observations of GRB990806
  90. GRB 990806, Optical Observations
  91. GRB 990806, optical observations
  92. GRB 990806, Optical Observations
  93. GRB990806 UBVRIJHK observations
  94. GRB990806: possible X-ray afterglow, BeppoSAX
  95. BeppoSAX ALERT GRB990806: Summer GRB
  96. GRB 990712 Optical Observations
  97. GRB990705: No Evidence for Neutrino Signal
  98. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  99. VLT spectrum of GRB990712
  100. GRB 990712

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