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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"

37095 results found.

  1. GRB991208 15-GHz observations
  2. GRB 991208 - OVRO detection
  3. GRB 991208 Optical Decay
  4. GRB 991208 optical observations
  5. GRB 991208 optical observations
  6. GRB 991208: Radio Observations
  7. IPN localization of GRB991208
  8. Optical Observations of GRB991105
  9. GRB991106: BeppoSAX/BATSE results
  10. GRB 991106, optical observations
  11. GRB991106, near-infrared observations
  12. BeppoSAX NFI Observation of GRB991106
  13. GRB 991106, radio observations
  14. GRB991106: the first BeppoSAX short GRB detection?
  15. GRB 991105: BATSE Observations
  16. IPN localization of GRB991105
  17. GRB 991106 Optical Observations
  18. GRB 991105, optical observations
  19. GRB991106, optical observation at SAO-RAS
  20. GRB 991106, LOTIS Optical Observations
  21. GRB 991106, optical observations
  22. BeppoSAX GRB Alert: GRB991106
  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. IPN localization of GRB990907
  45. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  46. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  47. GRB 990712 Late Optical Decay and Host Galaxy
  48. GRB 990712, Optical Observation
  49. GRB990806: BATSE Observations
  50. GRB 990806 Optical observations
  51. Optical Observations of GRB990806
  52. GRB 990806, Optical Observations
  53. GRB 990806, optical observations
  54. GRB 990806, Optical Observations
  55. GRB990806 UBVRIJHK observations
  56. GRB990806: possible X-ray afterglow, BeppoSAX
  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. BeppoSAX GRB990705: possible X-ray afterglow
  73. GRB 990704 X-ray Observations
  74. GRB 990704 Optical Observations
  75. GRB 990704, optical observations
  76. GRB990704
  77. GRB990705: Intriguing Positional Coincidences
  78. GRB990704
  79. GRB990704, optical observations
  80. GRB990704: possible X-ray afterglow
  81. Identification of a possible optical counterpart for GRB990704
  82. GRB990704
  83. Refined BeppoSAX-WFC position of GRB990704
  84. GRB990704: BeppoSAX detection
  85. Optical Observations of GRB990627
  86. GRB 990627, radio observations
  87. GRB990627: BeppoSAX-WFC final location
  88. BeppoSAX: GRB990625
  89. Late-time HST/STIS Observation of GRB 990123
  90. GRB 990506 - clarification to GCN 352
  91. GRB 990506 - Optical Observations
  92. Optical Observations of GRB 990506
  93. GRB 990506 Radio Transient
  94. GRB990527 Optical Observations
  95. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  96. IPN error box for GRB990527
  97. Late Afterglows of GRBs 990510, 990123
  98. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  99. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  100. X-ray/GRB 1SAX J0835.9+5118, Optical Observations

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