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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"

20353 results found.

  1. GRB000210 X-ray afterglow
  2. GRB000214: X-ray afterglow candidate
  3. GRB000214 refined BeppoSAX-WFC position
  4. Optical observations of the Chandra X-ray source for GRB000210
  5. GRB000210, Radio Observations
  6. GRB000201, Radio Observations
  7. GRB000210: BeppoSAX GRBM and WFC Detection
  8. GRB000201 Optical Observations
  9. GRB 000131 Optical Observations
  10. GRB000126 Optical Observations
  11. BATSE GRB trigger criteria changed
  12. BATSE+IPN location of GRB000131
  13. IPN localization of GRB000131
  14. GRB 000126, optical observations
  15. GRB991216, UBVRIJHK field photometry
  16. GCN resumes full operations
  17. IPN error boxes for GRB991229
  18. GRB 991216: J band spectrophotometry
  19. GRB 991216: Detection of the Host and/or Absorber Galaxy
  20. GRB 991216 RXTE ASM Observations
  21. GRB 991216: Updated BATSE parameters
  22. GRB 991217 (SAX J2303.2+0015) Optical observations
  23. Chandra observation of the X-ray afterglow of GRB991216
  24. SAX J2303.2+0015 Optical observations
  25. IR observations of GRB991216
  26. GRB 991217 (SAX J2303.2+0015) Optical observations
  27. GRB 991216 Radio Observations
  28. GRB 991208 Keck Spectroscopy
  29. GRB 991208 Infrared Detection
  30. GRB991216
  31. GRB 991216--Summary of RXTE Observations
  32. GRB 991216 Optical Observations
  33. GRB 991216, optical observations
  34. GRB 991208 SAO-RAS Spectroscopy
  35. SAX J2303.2+0015: an x-ray/GRB?
  36. GRB 991216, Optical Transient
  37. GRB991216 ('Beethoven Burst') B, R, and K Observations
  38. GRB991216, infrared observations
  39. GRB 991208 optical observations
  40. GRB 991216 Optical Observation
  41. GRB 991208 Keck Spectroscopy
  42. GRB 991216: Extremely bright BATSE burst
  43. GRB991208, optical observations
  44. GRB 991208, Optical Observation
  45. GRB991208, optical observations
  46. GRB 991208 Optical Decay
  47. IPN localization of GRB991208
  48. Optical Observations of GRB991105
  49. GRB991106: BeppoSAX/BATSE results
  50. BeppoSAX NFI Observation of GRB991106
  51. GRB 991106, radio observations
  52. GRB991106: the first BeppoSAX short GRB detection?
  53. GRB 991106 Optical Observations
  54. GRB991106, optical observation at SAO-RAS
  55. GRB 991106, LOTIS Optical Observations
  56. BeppoSAX GRB Alert: GRB991106
  57. GRB991105: SAX-GRBM/-WFC detection
  58. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  59. GRB 991014, Optical Observations
  60. GRB 991014 - BeppoSAX NFI observations
  61. GRB 991014, radio observations
  62. GRB 991014, Optical Observations
  63. GRB 991014, optical observations
  64. Optical Observations of GRB990907
  65. GRB990907: BeppoSAX follow up and X-ray afterglow
  66. GRB990907 and 990908
  67. GRB 990712 Late Optical Decay and Host Galaxy
  68. GRB 990712, Optical Observation
  69. GRB990806 BeppoSAX follow up
  70. GRB 990806 Optical observations
  71. GRB 990806, optical observations
  72. GRB 990806, Optical Observations
  73. GRB 990712 Optical Observations
  74. GRB 990712
  75. Late-time HST/STIS Observations of GRB 990510
  76. BeppoSAX NFI Observation of GRB990705
  77. BeppoSAX NFI Observation of GRB990705
  78. GRB 990705, R-band observations
  79. GRB990704: SAX-NFI results summary
  80. GRB990704 radio and optical observations
  81. GRB990704
  82. GRB990704, optical observations
  83. GRB990704
  84. Refined BeppoSAX-WFC position of GRB990704
  85. GRB990704: BeppoSAX detection
  86. Late-time HST/STIS Observation of GRB 990123
  87. Optical Observations of GRB 990506
  88. GRB990527 Optical Observations
  89. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  90. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  91. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  92. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  93. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  94. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  95. radio observations of X-ray/GRB transient field
  96. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  97. Optical report on X-ray/GRB transient
  98. GRB 990510: optical linear polarization
  99. GRB 990510: optical observations
  100. GRB990510, VI observations

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