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

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