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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').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

36077 results found.

  1. GRB 991208 optical observations
  2. GRB 991208: Radio Observations
  3. IPN localization of GRB991208
  4. Optical Observations of GRB991105
  5. GRB991106: BeppoSAX/BATSE results
  6. GRB 991106, optical observations
  7. GRB991106, near-infrared observations
  8. BeppoSAX NFI Observation of GRB991106
  9. GRB 991106, radio observations
  10. GRB991106: the first BeppoSAX short GRB detection?
  11. GRB 991105: BATSE Observations
  12. IPN localization of GRB991105
  13. GRB 991106 Optical Observations
  14. GRB 991105, optical observations
  15. GRB991106, optical observation at SAO-RAS
  16. GRB 991106, LOTIS Optical Observations
  17. GRB 991106, optical observations
  18. BeppoSAX GRB Alert: GRB991106
  19. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  20. GRB ALERT: GRB991105
  21. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  22. GRB 991014, Optical Observations
  23. GRB 991014 - BeppoSAX NFI observations
  24. GRB 991014, Optical Observations
  25. GRB 991014, radio observations
  26. GRB991014 BATSE Observations
  27. GRB 991014, Optical Observations
  28. GRB 991014, optical observations
  29. Super-LOTIS optical observation of GRB991014
  30. IPN/NFI error box for GRB991014
  31. IPN localization of GRB991014 - CORRECTION
  32. IPN localization of GRB991014
  33. BeppoSAX ALERT: GRB991014
  34. GRB 990915 optical observations
  35. GRB 990907 optical observations
  36. BATSE GRB trigger criteria
  37. Optical Observations of GRB990907
  38. IPN error box for GRB990915 (=BATSE 7766)
  39. IPN localization of BATSE #7766 (GRB990915)
  40. IPN localization of GRB990907
  41. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  42. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  43. GRB 990712 Late Optical Decay and Host Galaxy
  44. GRB 990712, Optical Observation
  45. GRB990806: BATSE Observations
  46. GRB 990806 Optical observations
  47. Optical Observations of GRB990806
  48. GRB 990806, Optical Observations
  49. GRB 990806, optical observations
  50. GRB 990806, Optical Observations
  51. GRB990806 UBVRIJHK observations
  52. BeppoSAX ALERT GRB990806: Summer GRB
  53. GRB 990712 Optical Observations
  54. GRB990705: No Evidence for Neutrino Signal
  55. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  56. VLT spectrum of GRB990712
  57. GRB 990712
  58. Late-time HST/STIS Observations of GRB 990510
  59. Refined BeppoSAX-WFC position of GRB990712
  60. GRB 990705, R-band observations
  61. Updated IPN localization of GRB990705
  62. IPN localization of GRB990704
  63. IPN localization of GRB990705
  64. Infrared and Optical Observations of GRB990705
  65. GRB 990705, radio observations
  66. GRB990704 radio and optical observations
  67. GRB 990704 X-ray Observations
  68. GRB 990704 Optical Observations
  69. GRB 990704, optical observations
  70. GRB990704
  71. GRB990705: Intriguing Positional Coincidences
  72. GRB990704
  73. GRB990704, optical observations
  74. Identification of a possible optical counterpart for GRB990704
  75. GRB990704
  76. Refined BeppoSAX-WFC position of GRB990704
  77. GRB990704: BeppoSAX detection
  78. Optical Observations of GRB990627
  79. GRB 990627, radio observations
  80. GRB990627: BeppoSAX-WFC final location
  81. BeppoSAX: GRB990625
  82. Late-time HST/STIS Observation of GRB 990123
  83. GRB 990506 - clarification to GCN 352
  84. GRB 990506 - Optical Observations
  85. Optical Observations of GRB 990506
  86. GRB 990506 Radio Transient
  87. GRB990527 Optical Observations
  88. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  89. IPN error box for GRB990527
  90. Late Afterglows of GRBs 990510, 990123
  91. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  92. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  93. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  94. GRB 990506 optical observation
  95. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  98. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  99. radio observations of X-ray/GRB transient field
  100. optical observation of the X-ray/GRB transient SAX J0835.9+5118

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