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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').
Advanced Search

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"

36784 results found.

  1. GRB 991216: Extremely bright BATSE burst
  2. GRB991208, optical observations
  3. GRB 991208 Keck Spectroscopy
  4. GRB991208 - millimeter detection
  5. GRB 991208, Optical Observation
  6. GRB 991208 - OVRO detection
  7. GRB 991208 Optical Decay
  8. GRB 991208 optical observations
  9. GRB 991208 optical observations
  10. GRB 991208: Radio Observations
  11. IPN localization of GRB991208
  12. Optical Observations of GRB991105
  13. GRB991106: BeppoSAX/BATSE results
  14. GRB 991106, optical observations
  15. GRB991106, near-infrared observations
  16. BeppoSAX NFI Observation of GRB991106
  17. GRB 991106, radio observations
  18. GRB991106: the first BeppoSAX short GRB detection?
  19. GRB 991105: BATSE Observations
  20. IPN localization of GRB991105
  21. GRB 991106 Optical Observations
  22. GRB 991105, optical observations
  23. GRB991106, optical observation at SAO-RAS
  24. GRB 991106, LOTIS Optical Observations
  25. GRB 991106, optical observations
  26. BeppoSAX GRB Alert: GRB991106
  27. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  28. GRB ALERT: GRB991105
  29. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  30. GRB 991014, Optical Observations
  31. GRB 991014 - BeppoSAX NFI observations
  32. GRB 991014, Optical Observations
  33. GRB 991014, radio observations
  34. GRB991014 BATSE Observations
  35. GRB 991014, Optical Observations
  36. GRB 991014, optical observations
  37. Super-LOTIS optical observation of GRB991014
  38. IPN/NFI error box for GRB991014
  39. IPN localization of GRB991014 - CORRECTION
  40. IPN localization of GRB991014
  41. BeppoSAX ALERT: GRB991014
  42. GRB 990915 optical observations
  43. GRB 990907 optical observations
  44. BATSE GRB trigger criteria
  45. Optical Observations of GRB990907
  46. IPN error box for GRB990915 (=BATSE 7766)
  47. IPN localization of BATSE #7766 (GRB990915)
  48. IPN localization of GRB990907
  49. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  50. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  51. GRB 990712 Late Optical Decay and Host Galaxy
  52. GRB 990712, Optical Observation
  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. BeppoSAX ALERT GRB990806: Summer GRB
  61. GRB 990712 Optical Observations
  62. GRB990705: No Evidence for Neutrino Signal
  63. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  64. VLT spectrum of GRB990712
  65. GRB 990712
  66. Late-time HST/STIS Observations of GRB 990510
  67. Refined BeppoSAX-WFC position of GRB990712
  68. GRB 990705, R-band observations
  69. Updated IPN localization of GRB990705
  70. IPN localization of GRB990704
  71. IPN localization of GRB990705
  72. Infrared and Optical Observations of GRB990705
  73. GRB 990705, radio observations
  74. GRB990704 radio and optical observations
  75. GRB 990704 X-ray Observations
  76. GRB 990704 Optical Observations
  77. GRB 990704, optical observations
  78. GRB990704
  79. GRB990705: Intriguing Positional Coincidences
  80. GRB990704
  81. GRB990704, optical observations
  82. Identification of a possible optical counterpart for GRB990704
  83. GRB990704
  84. Refined BeppoSAX-WFC position of GRB990704
  85. GRB990704: BeppoSAX detection
  86. Optical Observations of GRB990627
  87. GRB 990627, radio observations
  88. GRB990627: BeppoSAX-WFC final location
  89. BeppoSAX: GRB990625
  90. Late-time HST/STIS Observation of GRB 990123
  91. GRB 990506 - clarification to GCN 352
  92. GRB 990506 - Optical Observations
  93. Optical Observations of GRB 990506
  94. GRB 990506 Radio Transient
  95. GRB990527 Optical Observations
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. IPN error box for GRB990527
  98. Late Afterglows of GRBs 990510, 990123
  99. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  100. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation

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