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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"

20354 results found.

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

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