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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"

26363 results found.

  1. GRB 050502b, Optical observations
  2. GRB050502a: P60 Observations (Correction)
  3. GRB050502a: P60 Observations
  4. Renewal of SGR 1806-20 activity
  5. GRB050502B Swift-BAT refined analysis
  6. Swift UVOT refined analysis
  7. GRB 050502a : R band observation at Lulin observatory
  8. GRB 050502b : optical observation at Lulin observatory
  9. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  10. Swift Detection of the Bright Burst GRB050502b
  11. GRB 050502: INTEGRAL results
  12. GRB 050502: ROTSE-III Detection of Possible Counterpart
  13. Swift/BAT possible detection of a weak burst GRB050430
  14. GRB050416a: Radio Detection
  15. GRB 050422: Swift-UVOT observation
  16. GRB 050422: Swift-BAT refined analysis
  17. Swift Detection of GRB 050422
  18. GRB 050421: SLOTIS observations
  19. GRB 050421: Further Analysis of IR imaging
  20. GRB050421: Radio Observations
  21. GRB050421: Radio Observations
  22. GRB 050421: IR Observations
  23. GRB 050421: Swift-BAT refined analysis
  24. GRB050421
  25. GRB 050421: early Swift XRT analysis results
  26. GRB 050421: NIR observations
  27. GRB050421: P60 Observations
  28. GRB 050421: BOOTES-2 simultaneous optical observations
  29. GRB 050416b: Tentative Swift XRT Position
  30. GRB 050315: potential host galaxy
  31. GRB050326: analysis of the XMM-Newton observation
  32. GRB050418: Null Optical Observations
  33. GRB050416A, optical observations
  34. GRB 050418: Swift-BAT refined analysis
  35. GRB 050416: Mitsume optical observation
  36. GRB050416B: IR observations
  37. GRB050412: Radio Observations
  38. GRB 050416: Swift/UVOT detection of afterglow emission
  39. GRB050416: Refined Swift-XRT analysis
  40. GRB 050416,optical observation
  41. GRB050416: P200 NIR Observations
  42. GRB 050416: Radio observations
  43. Swift BAT/XRT Detection of GRB 050416
  44. GRB 050412: PROMPT VRcIc Observations
  45. GRB 050408: Kuiper 1.5m observations
  46. GRB 050412: early Swift XRT analysis results
  47. GRB 050412: Early Optical/Ultraviolet Observations with
  48. GRB 050408: SDSS Field Calibration
  49. GRB050412: P60 Observations
  50. GRB 050412: Swift XRT Position
  51. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  52. GRB 050412: IR and Optical observations
  53. GRB 050412: IR Observations
  54. GRB050408: Radio Observations
  55. GRB 050401: Optical limit
  56. GRB050410: P60 Observations
  57. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  58. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  59. GRB050410: Radio Observations
  60. GRB050410: MASTER optical observations
  61. GRB 050410: Early observations with Swift-UVOT
  62. Swift-BAT detection of GRB 050410
  63. GRB 050408: Inconsistency of host galaxy identification
  64. GRB 050408: Subaru Observations
  65. GRB 050408: WIDGET simultaneous optical observations
  66. GRB 050408: Properties of the Host Galaxy
  67. GRB050408: Radio Observations
  68. GRB 050408: Swift XRT analysis
  69. GRB 050408: Optical limit at 20 min after the burst
  70. GRB050408: REM NIR and Optical observation
  71. GRB 050408,optical observation
  72. GRB 050408: Mercator Optical Observations
  73. GRB 050408: Optical afterglow confirmed
  74. GRB 050408: opitcal observation
  75. GRB 050408, optical observations
  76. GRB 050408 optical candidate
  77. GRB 050408: Swift XRT Position
  78. GRB050408: MASTER optical observations
  79. GRB050401: Radio Detection
  80. GRB 050406: early Swift XRT analysis results
  81. GRB 050406 BAT refined analysis
  82. GRB 050406: Early observations with Swift-UVOT
  83. Swift-BAT detection of GRB 050406
  84. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  85. GRB 050401: VLT spectroscopic redshift
  86. GRB 050401 BAT refined analysis
  87. GRB050401: TNG R-band observation
  88. GRB 050402: Early observations with Swift-UVOT
  89. Swift Trigger 113225: P60 Observations
  90. GRB 050401: Optical afterglow confirmed
  91. GRB 050401: Prompt XRT position
  92. Retraction of three Swift GRB triggers
  93. GRB050331: No Afterglow Detected
  94. Swift-BAT detection of GRB 050331b
  95. GRB 050331: Swift UVOT Source
  96. Swift-BAT detection of GRB 050331
  97. GRB 050326: Early observations with Swift-UVOT
  98. GRB 050326 XMM-Newton observation
  99. GRB 050326: Swift XRT Position
  100. GRB 050326 BAT refined analysis

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