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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. GRB 991208 optical observations
  3. GRB 991208: Radio Observations
  4. IPN localization of GRB991208
  5. Optical Observations of GRB991105
  6. GRB991106: BeppoSAX/BATSE results
  7. GRB 991106, optical observations
  8. GRB991106, near-infrared observations
  9. BeppoSAX NFI Observation of GRB991106
  10. GRB 991106, radio observations
  11. GRB991106: the first BeppoSAX short GRB detection?
  12. GRB 991105: BATSE Observations
  13. IPN localization of GRB991105
  14. GRB 991106 Optical Observations
  15. GRB 991105, optical observations
  16. GRB991106, optical observation at SAO-RAS
  17. GRB 991106, LOTIS Optical Observations
  18. GRB 991106, optical observations
  19. BeppoSAX refined position for GRB991106
  20. BeppoSAX GRB Alert: GRB991106
  21. Revised BeppoSAX WFC position of GRB991105
  22. GRB991105: SAX-GRBM/-WFC detection
  23. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  24. GRB ALERT: GRB991105
  25. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  26. GRB 991014, Optical Observations
  27. GRB 991014 - BeppoSAX NFI observations
  28. GRB 991014, Optical Observations
  29. GRB 991014, radio observations
  30. GRB991014 BATSE Observations
  31. GRB 991014, Optical Observations
  32. GRB 991014, optical observations
  33. Super-LOTIS optical observation of GRB991014
  34. IPN/NFI error box for GRB991014
  35. IPN localization of GRB991014 - CORRECTION
  36. IPN localization of GRB991014
  37. BeppoSAX ALERT: GRB991014
  38. GRB 990915 optical observations
  39. GRB 990907 optical observations
  40. BATSE GRB trigger criteria
  41. Optical Observations of GRB990907
  42. IPN error box for GRB990915 (=BATSE 7766)
  43. IPN localization of BATSE #7766 (GRB990915)
  44. GRB990907: BeppoSAX follow up and X-ray afterglow
  45. GRB990907 and 990908
  46. IPN localization of GRB990907
  47. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  48. GRB990907: refined WFC position
  49. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  50. GRB 990712 Late Optical Decay and Host Galaxy
  51. GRB 990712, Optical Observation
  52. GRB990806 BeppoSAX follow up
  53. GRB990806: BATSE Observations
  54. GRB 990806 Optical observations
  55. Optical Observations of GRB990806
  56. GRB 990806, Optical Observations
  57. GRB 990806, optical observations
  58. GRB 990806, Optical Observations
  59. GRB990806 UBVRIJHK observations
  60. GRB990806: possible X-ray afterglow, BeppoSAX
  61. BeppoSAX ALERT GRB990806: Summer GRB
  62. GRB 990712 Optical Observations
  63. GRB990705: No Evidence for Neutrino Signal
  64. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  65. VLT spectrum of GRB990712
  66. GRB 990712
  67. Late-time HST/STIS Observations of GRB 990510
  68. Refined BeppoSAX-WFC position of GRB990712
  69. BeppoSAX NFI Observation of GRB990705
  70. BeppoSAX NFI Observation of GRB990705
  71. Updated Astrometry for the IR Counterpart of GRB990705
  72. GRB 990705, R-band observations
  73. Updated IPN localization of GRB990705
  74. IPN localization of GRB990704
  75. IPN localization of GRB990705
  76. Infrared and Optical Observations of GRB990705
  77. GRB 990705, radio observations
  78. GRB990704: SAX-NFI results summary
  79. GRB990704 radio and optical observations
  80. BeppoSAX GRB990705: possible X-ray afterglow
  81. GRB 990704 X-ray Observations
  82. GRB 990704 Optical Observations
  83. GRB 990704, optical observations
  84. GRB990704
  85. GRB990705: Intriguing Positional Coincidences
  86. GRB990704
  87. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  88. GRB990704, optical observations
  89. GRB990704: possible X-ray afterglow
  90. Identification of a possible optical counterpart for GRB990704
  91. GRB990704
  92. Refined BeppoSAX-WFC position of GRB990704
  93. GRB990704: BeppoSAX detection
  94. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  95. Optical Observations of GRB990627
  96. GRB 990627, radio observations
  97. GRB990627: BeppoSAX-WFC final location
  98. BeppoSAX: GRB990625
  99. Late-time HST/STIS Observation of GRB 990123
  100. GRB 990506 - clarification to GCN 352

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