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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"

20361 results found.

  1. GRB 000214 near-IR observations
  2. GRB 000214, Radio Observations
  3. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  4. GRB000210, Radio Observations
  5. GRB 000115, BVRI field photometry
  6. GRB000214: BeppoSAX GRBM and WFC Detection
  7. BATSE GRB trigger criterion changed
  8. Optical observations of GRB000210
  9. GRB000210 X-ray afterglow
  10. GRB000214: X-ray afterglow candidate
  11. GRB000214 refined BeppoSAX-WFC position
  12. Optical observations of the Chandra X-ray source for GRB000210
  13. GRB000210, Radio Observations
  14. GRB000201, Radio Observations
  15. GRB000210: BeppoSAX GRBM and WFC Detection
  16. GRB000201 Optical Observations
  17. GRB 000131 Optical Observations
  18. GRB000126 Optical Observations
  19. BATSE GRB trigger criteria changed
  20. BATSE+IPN location of GRB000131
  21. IPN localization of GRB000131
  22. GRB 000126, optical observations
  23. GRB991216, UBVRIJHK field photometry
  24. GCN resumes full operations
  25. IPN error boxes for GRB991229
  26. GRB 991216: J band spectrophotometry
  27. GRB 991216: Detection of the Host and/or Absorber Galaxy
  28. GRB 991216 RXTE ASM Observations
  29. GRB 991216: Updated BATSE parameters
  30. GRB 991217 (SAX J2303.2+0015) Optical observations
  31. Chandra observation of the X-ray afterglow of GRB991216
  32. SAX J2303.2+0015 Optical observations
  33. IR observations of GRB991216
  34. GRB 991217 (SAX J2303.2+0015) Optical observations
  35. GRB 991216 Radio Observations
  36. GRB 991208 Keck Spectroscopy
  37. GRB 991208 Infrared Detection
  38. GRB991216
  39. GRB 991216--Summary of RXTE Observations
  40. GRB 991216 Optical Observations
  41. GRB 991216, optical observations
  42. GRB 991208 SAO-RAS Spectroscopy
  43. SAX J2303.2+0015: an x-ray/GRB?
  44. GRB 991216, Optical Transient
  45. GRB991216 ('Beethoven Burst') B, R, and K Observations
  46. GRB991216, infrared observations
  47. GRB 991208 optical observations
  48. GRB 991216 Optical Observation
  49. GRB 991208 Keck Spectroscopy
  50. GRB 991216: Extremely bright BATSE burst
  51. GRB991208, optical observations
  52. GRB 991208, Optical Observation
  53. GRB991208, optical observations
  54. GRB 991208 Optical Decay
  55. IPN localization of GRB991208
  56. Optical Observations of GRB991105
  57. GRB991106: BeppoSAX/BATSE results
  58. BeppoSAX NFI Observation of GRB991106
  59. GRB 991106, radio observations
  60. GRB991106: the first BeppoSAX short GRB detection?
  61. GRB 991106 Optical Observations
  62. GRB991106, optical observation at SAO-RAS
  63. GRB 991106, LOTIS Optical Observations
  64. BeppoSAX GRB Alert: GRB991106
  65. GRB991105: SAX-GRBM/-WFC detection
  66. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  67. GRB 991014, Optical Observations
  68. GRB 991014 - BeppoSAX NFI observations
  69. GRB 991014, radio observations
  70. GRB 991014, Optical Observations
  71. GRB 991014, optical observations
  72. Optical Observations of GRB990907
  73. GRB990907: BeppoSAX follow up and X-ray afterglow
  74. GRB990907 and 990908
  75. GRB 990712 Late Optical Decay and Host Galaxy
  76. GRB 990712, Optical Observation
  77. GRB990806 BeppoSAX follow up
  78. GRB 990806 Optical observations
  79. GRB 990806, optical observations
  80. GRB 990806, Optical Observations
  81. GRB 990712 Optical Observations
  82. GRB 990712
  83. Late-time HST/STIS Observations of GRB 990510
  84. BeppoSAX NFI Observation of GRB990705
  85. BeppoSAX NFI Observation of GRB990705
  86. GRB 990705, R-band observations
  87. GRB990704: SAX-NFI results summary
  88. GRB990704 radio and optical observations
  89. GRB990704
  90. GRB990704, optical observations
  91. GRB990704
  92. Refined BeppoSAX-WFC position of GRB990704
  93. GRB990704: BeppoSAX detection
  94. Late-time HST/STIS Observation of GRB 990123
  95. Optical Observations of GRB 990506
  96. GRB990527 Optical Observations
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  98. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  99. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  100. X-ray/GRB 1SAX J0835.9+5118, Optical Observation

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