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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"

20258 results found.

  1. Renewal of SGR 1806-20 activity
  2. GRB050502A: Optical Observations
  3. GRB050502B Swift-BAT refined analysis
  4. GRB 050502b: Swift XRT Position
  5. Swift Detection of the Bright Burst GRB050502b
  6. GRB050502: ANU 1m optical Observations
  7. GRB 050502: ROTSE-III Detection of Possible Counterpart
  8. Swift/BAT possible detection of a weak burst GRB050430
  9. GRB050416a: Radio Detection
  10. GRB 050422: Swift-UVOT observation
  11. GRB 050422: Swift XRT Position
  12. Swift Detection of GRB 050422
  13. GRB 050421: SLOTIS observations
  14. GRB 050421: Further Analysis of IR imaging
  15. GRB050421: Radio Observations
  16. GRB050421: Radio Observations
  17. GRB 050421: IR Observations
  18. GRB 050421: ROTSE-III Optical Limits
  19. GRB050421
  20. GRB 050421: early Swift XRT analysis results
  21. GRB 050421: NIR observations
  22. GRB050421: P60 Observations
  23. GRB 050421: BOOTES-2 simultaneous optical observations
  24. Swift Detection of GRB050421
  25. GRB 050416b: Tentative Swift XRT Position
  26. GRB 050315: potential host galaxy
  27. GRB050326: analysis of the XMM-Newton observation
  28. GRB050418: Null Optical Observations
  29. GRB 050412: Chandra observations
  30. GRB050416A, optical observations
  31. GRB 050418: Swift-BAT refined analysis
  32. GRB 050416: Mitsume optical observation
  33. GRB 050416b: LCO observations
  34. GRB 050416b: LCO observations
  35. GRB050416B: IR observations
  36. GRB 050416: Swift/UVOT refined analysis
  37. Swift-BAT detection of GRB 050416b
  38. GRB050412: Radio Observations
  39. GRB 050416: Swift/UVOT detection of afterglow emission
  40. GRB050416: Refined Swift-XRT analysis
  41. GRB 050416,optical observation
  42. GRB050416: P200 NIR Observations
  43. GRB 050416: Swift XRT Position
  44. GRB 050416: Radio observations
  45. Swift BAT/XRT Detection of GRB 050416
  46. GRB 050412: Subaru observations
  47. GRB 050408: RTT150 optical observations
  48. GRB 050412: PROMPT VRcIc Observations
  49. GRB 050408: Kuiper 1.5m observations
  50. GRB 050412: optical observations
  51. GRB 050412: early Swift XRT analysis results
  52. GRB 050412: Swift-BAT refined analysis
  53. GRB 050412: Early Optical/Ultraviolet Observations with
  54. GRB 050408: SDSS Field Calibration
  55. GRB050412: P60 Observations
  56. GRB 050412: Swift XRT Position
  57. GRB050412: ROTSE-III Optical Limits
  58. GRB 050412: IR and Optical observations
  59. GRB 050412: IR Observations
  60. GRB050408: Radio Observations
  61. GRB050410: P60 Observations
  62. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  63. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  64. GRB050410: Radio Observations
  65. GRB050410: MASTER optical observations
  66. GRB 050410: Early observations with Swift-UVOT
  67. GRB 050410: Swift XRT Position
  68. GRB 050408: Inconsistency of host galaxy identification
  69. GRB 050408: Subaru Observations
  70. GRB 050408: WIDGET simultaneous optical observations
  71. GRB 050408: Properties of the Host Galaxy
  72. GRB050408: Radio Observations
  73. GRB 050408: Swift XRT analysis
  74. GRB050408: REM NIR and Optical observation
  75. GRB 050408,optical observation
  76. GRB 050408: Mercator Optical Observations
  77. GRB 050408: Optical afterglow confirmed
  78. GRB 050408: opitcal observation
  79. GRB 050408, optical observations
  80. GRB 050408: Swift XRT Position
  81. GRB 050408: ROTSE-III Optical Limits
  82. GRB050408: MASTER optical observations
  83. GRB050401: Radio Detection
  84. GRB 050406: Magellan optical observations
  85. GRB 050406: early Swift XRT analysis results
  86. GRB 050406 BAT refined analysis
  87. GRB 050406: Early observations with Swift-UVOT
  88. GRB 050406: Swift XRT Position
  89. Swift-BAT detection of GRB 050406
  90. Konus-Wind observation of GRB 050401
  91. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  92. GRB 050401 BAT refined analysis
  93. GRB050401: TNG R-band observation
  94. GRB 050402: Early observations with Swift-UVOT
  95. Swift Trigger 113225: P60 Observations
  96. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  97. GRB 050401: Optical afterglow confirmed
  98. Swift-BAT detection of GRB 050401
  99. GRB050331: No Afterglow Detected
  100. GRB 050331: Swift UVOT Source

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