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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"

28054 results found.

  1. Swift Detection of the Bright Burst GRB050502b
  2. GRB 050502: INTEGRAL results
  3. GRB 050502: ROTSE-III Detection of Possible Counterpart
  4. Swift/BAT possible detection of a weak burst GRB050430
  5. GRB050416a: Radio Detection
  6. GRB 050422: Swift-UVOT observation
  7. GRB 050422: Swift-BAT refined analysis
  8. Swift Detection of GRB 050422
  9. GRB 050421: SLOTIS observations
  10. GRB 050421: Further Analysis of IR imaging
  11. GRB050421: Radio Observations
  12. GRB050421: Radio Observations
  13. GRB 050421: IR Observations
  14. GRB 050421: Swift-BAT refined analysis
  15. GRB050421
  16. GRB 050421: early Swift XRT analysis results
  17. GRB 050421: NIR observations
  18. GRB050421: P60 Observations
  19. GRB 050421: BOOTES-2 simultaneous optical observations
  20. GRB 050416b: Tentative Swift XRT Position
  21. GRB 050315: potential host galaxy
  22. GRB050326: analysis of the XMM-Newton observation
  23. GRB050418: Null Optical Observations
  24. GRB050416A, optical observations
  25. GRB 050418: Swift-BAT refined analysis
  26. GRB 050416: Mitsume optical observation
  27. GRB050416B: IR observations
  28. GRB050412: Radio Observations
  29. GRB 050416: Swift/UVOT detection of afterglow emission
  30. GRB050416: Refined Swift-XRT analysis
  31. GRB 050416,optical observation
  32. GRB050416: P200 NIR Observations
  33. GRB 050416: Radio observations
  34. Swift BAT/XRT Detection of GRB 050416
  35. GRB 050412: PROMPT VRcIc Observations
  36. GRB 050408: Kuiper 1.5m observations
  37. GRB 050412: early Swift XRT analysis results
  38. GRB 050412: Early Optical/Ultraviolet Observations with
  39. GRB 050408: SDSS Field Calibration
  40. GRB050412: P60 Observations
  41. GRB 050412: Swift XRT Position
  42. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  43. GRB 050412: IR and Optical observations
  44. GRB 050412: IR Observations
  45. GRB050408: Radio Observations
  46. GRB 050401: Optical limit
  47. GRB050410: P60 Observations
  48. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  49. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  50. GRB050410: Radio Observations
  51. GRB050410: MASTER optical observations
  52. GRB 050410: Early observations with Swift-UVOT
  53. Swift-BAT detection of GRB 050410
  54. GRB 050408: Inconsistency of host galaxy identification
  55. GRB 050408: Subaru Observations
  56. GRB 050408: WIDGET simultaneous optical observations
  57. GRB 050408: Properties of the Host Galaxy
  58. GRB050408: Radio Observations
  59. GRB 050408: Swift XRT analysis
  60. GRB 050408: Optical limit at 20 min after the burst
  61. GRB050408: REM NIR and Optical observation
  62. GRB 050408,optical observation
  63. GRB 050408: Mercator Optical Observations
  64. GRB 050408: Optical afterglow confirmed
  65. GRB 050408: opitcal observation
  66. GRB 050408, optical observations
  67. GRB 050408 optical candidate
  68. GRB 050408: Swift XRT Position
  69. GRB050408: MASTER optical observations
  70. GRB050401: Radio Detection
  71. GRB 050406: early Swift XRT analysis results
  72. GRB 050406 BAT refined analysis
  73. GRB 050406: Early observations with Swift-UVOT
  74. Swift-BAT detection of GRB 050406
  75. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  76. GRB 050401: VLT spectroscopic redshift
  77. GRB 050401 BAT refined analysis
  78. GRB050401: TNG R-band observation
  79. GRB 050402: Early observations with Swift-UVOT
  80. Swift Trigger 113225: P60 Observations
  81. GRB 050401: Optical afterglow confirmed
  82. GRB 050401: Prompt XRT position
  83. Retraction of three Swift GRB triggers
  84. GRB050331: No Afterglow Detected
  85. Swift-BAT detection of GRB 050331b
  86. GRB 050331: Swift UVOT Source
  87. Swift-BAT detection of GRB 050331
  88. GRB 050326: Early observations with Swift-UVOT
  89. GRB 050326 XMM-Newton observation
  90. GRB 050326: Swift XRT Position
  91. GRB 050326 BAT refined analysis
  92. GRB050326: delayed XRT observation
  93. GRB050319, color indices
  94. GRB050319: optical observation, March 20-22
  95. GRB050319: RTT150 Optical Observations
  96. Swift-BAT trigger 112060 is not a real GRB
  97. GRB 050318: Swift-BAT refined analysis
  98. GRB050319: VLA Observations
  99. GRB050319: radio observation
  100. GRB 050319: Swift-UVOT detection of the afterglow

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Download all Circulars as a .tar.gz archive (updated once a day):
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