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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"

36681 results found.

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

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