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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"

24672 results found.

  1. GRB050502: P200 Observations (Correction)
  2. GRB050502: P200 Observations
  3. GRB 050504 : R band observation at Lulin observatory
  4. Swift UVOT observation of GRB 050504
  5. GRB 050504, R band Observations
  6. GRB 050502b, V band Observations
  7. GRB050504: P60 Observations
  8. GRB 050504: A long GRB detected with INTEGRAL
  9. GRB (?) 050504: IR Observations, Intriguing Source
  10. GRB 050502b, Optical observations
  11. GRB050502a: P60 Observations (Correction)
  12. GRB050502a: P60 Observations
  13. Renewal of SGR 1806-20 activity
  14. GRB050502B Swift-BAT refined analysis
  15. Swift UVOT refined analysis
  16. GRB 050502a : R band observation at Lulin observatory
  17. GRB 050502b : optical observation at Lulin observatory
  18. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  19. Swift Detection of the Bright Burst GRB050502b
  20. GRB 050502: INTEGRAL results
  21. GRB 050502: ROTSE-III Detection of Possible Counterpart
  22. Swift/BAT possible detection of a weak burst GRB050430
  23. GRB050416a: Radio Detection
  24. GRB 050422: Swift-UVOT observation
  25. GRB 050422: Swift-BAT refined analysis
  26. Swift Detection of GRB 050422
  27. GRB 050421: SLOTIS observations
  28. GRB 050421: Further Analysis of IR imaging
  29. GRB050421: Radio Observations
  30. GRB050421: Radio Observations
  31. GRB 050421: IR Observations
  32. GRB 050421: Swift-BAT refined analysis
  33. GRB050421
  34. GRB 050421: early Swift XRT analysis results
  35. GRB 050421: NIR observations
  36. GRB050421: P60 Observations
  37. GRB 050421: BOOTES-2 simultaneous optical observations
  38. GRB 050416b: Tentative Swift XRT Position
  39. GRB 050315: potential host galaxy
  40. GRB050326: analysis of the XMM-Newton observation
  41. GRB050418: Null Optical Observations
  42. GRB050416A, optical observations
  43. GRB 050418: Swift-BAT refined analysis
  44. GRB 050416: Mitsume optical observation
  45. GRB050416B: IR observations
  46. GRB050412: Radio Observations
  47. GRB 050416: Swift/UVOT detection of afterglow emission
  48. GRB050416: Refined Swift-XRT analysis
  49. GRB 050416,optical observation
  50. GRB050416: P200 NIR Observations
  51. GRB 050416: Radio observations
  52. Swift BAT/XRT Detection of GRB 050416
  53. GRB 050412: PROMPT VRcIc Observations
  54. GRB 050408: Kuiper 1.5m observations
  55. GRB 050412: early Swift XRT analysis results
  56. GRB 050412: Early Optical/Ultraviolet Observations with
  57. GRB 050408: SDSS Field Calibration
  58. GRB050412: P60 Observations
  59. GRB 050412: Swift XRT Position
  60. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  61. GRB 050412: IR and Optical observations
  62. GRB 050412: IR Observations
  63. GRB050408: Radio Observations
  64. GRB 050401: Optical limit
  65. GRB050410: P60 Observations
  66. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  67. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  68. GRB050410: Radio Observations
  69. GRB050410: MASTER optical observations
  70. GRB 050410: Early observations with Swift-UVOT
  71. Swift-BAT detection of GRB 050410
  72. GRB 050408: Inconsistency of host galaxy identification
  73. GRB 050408: Subaru Observations
  74. GRB 050408: WIDGET simultaneous optical observations
  75. GRB 050408: Properties of the Host Galaxy
  76. GRB050408: Radio Observations
  77. GRB 050408: Swift XRT analysis
  78. GRB 050408: Optical limit at 20 min after the burst
  79. GRB050408: REM NIR and Optical observation
  80. GRB 050408,optical observation
  81. GRB 050408: Mercator Optical Observations
  82. GRB 050408: Optical afterglow confirmed
  83. GRB 050408: opitcal observation
  84. GRB 050408, optical observations
  85. GRB 050408 optical candidate
  86. GRB 050408: Swift XRT Position
  87. GRB050408: MASTER optical observations
  88. GRB050401: Radio Detection
  89. GRB 050406: early Swift XRT analysis results
  90. GRB 050406 BAT refined analysis
  91. GRB 050406: Early observations with Swift-UVOT
  92. Swift-BAT detection of GRB 050406
  93. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  94. GRB 050401: VLT spectroscopic redshift
  95. GRB 050401 BAT refined analysis
  96. GRB050401: TNG R-band observation
  97. GRB 050402: Early observations with Swift-UVOT
  98. Swift Trigger 113225: P60 Observations
  99. GRB 050401: Optical afterglow confirmed
  100. GRB 050401: Prompt XRT position

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