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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"

21664 results found.

  1. GRB 000126, optical observations
  2. IPN annulus for GRB000115
  3. GRB991216, UBVRIJHK field photometry
  4. GCN resumes full operations
  5. GRB 991216: Detection of the Host and/or Absorber Galaxy
  6. IPN error box for GRB991216
  7. GRB 991216: Updated BATSE parameters
  8. GRB 991217 (SAX J2303.2+0015) Optical observations
  9. Chandra observation of the X-ray afterglow of GRB991216
  10. SAX J2303.2+0015 Optical observations
  11. IR observations of GRB991216
  12. GRB 991217 (SAX J2303.2+0015) Optical observations
  13. Refined IPN localization of GRB991216
  14. GRB 991216 Radio Observations
  15. GRB 991208 Infrared Detection
  16. GRB991216
  17. GRB 991216--Summary of RXTE Observations
  18. GRB 991216 Optical Observations
  19. GRB 991216, optical observations
  20. GRB 991208 SAO-RAS Spectroscopy
  21. SAX J2303.2+0015: an x-ray/GRB?
  22. GRB 991216, Optical Transient
  23. GRB991216 ('Beethoven Burst') B, R, and K Observations
  24. GRB991216, infrared observations
  25. GRB 991208 optical observations
  26. GRB 991216 Optical Observation
  27. GRB 991216: Extremely bright BATSE burst
  28. GRB991208, optical observations
  29. GRB 991208, Optical Observation
  30. GRB991208, optical observations
  31. GRB 991208 Optical Decay
  32. Optical Observations of GRB991105
  33. GRB 991106, optical observations
  34. BeppoSAX NFI Observation of GRB991106
  35. GRB 991106, radio observations
  36. GRB991106: the first BeppoSAX short GRB detection?
  37. IPN localization of GRB991105
  38. GRB 991106 Optical Observations
  39. GRB991106, optical observation at SAO-RAS
  40. GRB 991106, LOTIS Optical Observations
  41. GRB991105: SAX-GRBM/-WFC detection
  42. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  43. GRB 991014, Optical Observations
  44. GRB 991014 - BeppoSAX NFI observations
  45. GRB 991014, radio observations
  46. GRB 991014, Optical Observations
  47. GRB 991014, optical observations
  48. IPN localization of GRB991014 - CORRECTION
  49. IPN localization of GRB991014
  50. Optical Observations of GRB990907
  51. IPN localization of BATSE #7766 (GRB990915)
  52. GRB990907: BeppoSAX follow up and X-ray afterglow
  53. GRB990907 and 990908
  54. IPN localization of GRB990907
  55. GRB990806 BeppoSAX follow up
  56. GRB 990806 Optical observations
  57. GRB 990806, Optical Observations
  58. GRB 990806, optical observations
  59. GRB 990806, Optical Observations
  60. BeppoSAX ALERT GRB990806: Summer GRB
  61. GRB 990712 Optical Observations
  62. GRB 990712
  63. Late-time HST/STIS Observations of GRB 990510
  64. BeppoSAX NFI Observation of GRB990705
  65. BeppoSAX NFI Observation of GRB990705
  66. GRB 990705, R-band observations
  67. Updated IPN localization of GRB990705
  68. IPN localization of GRB990704
  69. IPN localization of GRB990705
  70. Infrared and Optical Observations of GRB990705
  71. GRB 990705, radio observations
  72. GRB990704: SAX-NFI results summary
  73. GRB990704 radio and optical observations
  74. GRB990704
  75. GRB990704, optical observations
  76. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  77. Optical Observations of GRB990627
  78. GRB 990627, radio observations
  79. GRB990627: BeppoSAX-WFC final location
  80. Late-time HST/STIS Observation of GRB 990123
  81. Optical Observations of GRB 990506
  82. GRB990527 Optical Observations
  83. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  84. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  85. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  86. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  87. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  88. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  89. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  90. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  91. radio observations of X-ray/GRB transient field
  92. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  93. Optical report on X-ray/GRB transient
  94. radio detection of X-ray/GRB transient
  95. BeppoSAX: A new fast X-ray transient
  96. GRB990510: photometric and spectroscopic observations with the VLT
  97. GRB 990510: optical linear polarization
  98. GRB 990510: optical observations
  99. GRB990510, VI observations
  100. GRB 990506 R band observations

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