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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"
  1. GRB 050401: Rc observation
  2. GRB050416a: Radio Detection
  3. GRB 050422: Swift-UVOT observation
  4. GRB 050422: Swift-BAT refined analysis
  5. GRB 050422: Swift XRT Position
  6. Swift Detection of GRB 050422
  7. GRB 050421: NIR observations
  8. GRB 050416: Optical/NIR observations
  9. GRB 050421: SLOTIS observations
  10. GRB 050421: Further Analysis of IR imaging
  11. GRB050421: Radio Observations
  12. GRB050421: Radio Observations
  13. GRB 050421: Swift-UVOT observation
  14. GRB 050421: IR Observations
  15. GRB 050421: Swift-BAT refined analysis
  16. GRB 050421: ROTSE-III Optical Limits
  17. GRB 050421: NIR observations re-examination
  18. GRB050421
  19. GRB 050421: early Swift XRT analysis results
  20. GRB 050421: NIR observations
  21. GRB050421: P60 Observations
  22. GRB 050421: BOOTES-2 simultaneous optical observations
  23. GRB 050421: Optical observations at the INT
  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. Swift-BAT detection of the bright and long GRB 050418
  33. GRB 050416: Mitsume optical observation
  34. GRB 050416 : optical observation at Xinglong observatory
  35. GRB 050416B: optical observations
  36. GRB 050416b: Swift-BAT refined analysis
  37. GRB 050416b: LCO observations
  38. GRB 050416b: LCO observations
  39. GRB050416B: IR observations
  40. GRB 050416: Swift/UVOT refined analysis
  41. Swift-BAT detection of GRB 050416b
  42. IBAS GRB Alert # 2463: not a GRB
  43. GRB050412: Radio Observations
  44. GRB 050416: Swift/UVOT detection of afterglow emission
  45. GRB050416: Refined Swift-XRT analysis
  46. GRB050416: Maidanak optical observations
  47. GRB 050416: Swift-BAT refined analysis
  48. GRB 050416: ART observations
  49. GRB 050416,optical observation
  50. GRB 050416: KAIT observations
  51. GRB050416: P200 NIR Observations
  52. GRB 050416: Swift XRT Position
  53. GRB 050416: Radio observations
  54. Confirmation of OT for GRB050416
  55. GRB050416: P60 Afterglow Candidate
  56. Swift BAT/XRT Detection of GRB 050416
  57. GRB 050412: Subaru observations
  58. GRB 050408: RTT150 optical observations
  59. GRB050408: optical observation
  60. GRB 050412: PROMPT VRcIc Observations
  61. GRB 050408: Kuiper 1.5m observations
  62. GRB 050412: optical limit
  63. GRB 050412: optical observations
  64. GRB 050408: refined XRT analysis, no jet break seen yet
  65. GRB 050412: early Swift XRT analysis results
  66. GRB 050412 : XingLong optical observation
  67. GRB 050412: Swift-BAT refined analysis
  68. GRB 050412: ANU 2.3m observations
  69. GRB 050412: Early Optical/Ultraviolet Observations with
  70. GRB 050412: retraction of UVOT transient report
  71. GRB 050412: UVOT transient not in XRT error circle
  72. GRB 050408: SDSS Field Calibration
  73. GRB 050412: Optical limit
  74. GRB 050412: LCO Optical Observations
  75. GRB 050412: Optical observations
  76. GRB050412: P60 Observations
  77. GRB 050412: Swift XRT Position
  78. GRB050412: optical limit before and during GRB
  79. GRB 050412: LCO optical observations
  80. GRB050412: ROTSE-III Optical Limits
  81. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  82. GRB 050412: IR and Optical observations
  83. GRB 050412: IR Observations
  84. GRB050408: Radio Observations
  85. GRB 050401: Optical limit
  86. GRB 050408: Optical limit
  87. GRB050410: P60 Observations
  88. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  89. GRB 050410, optical observations
  90. GRB 050408: PROMPT VRcIc Observations
  91. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  92. GRB 050410 R band Optical Observations
  93. GRB050410 : Null detection report
  94. GRB 050410, optical observations
  95. GRB050410: Radio Observations
  96. GRB 050408: Swift XRT measurement of possible jet break
  97. GRB050410: MASTER optical observations
  98. GRB 050410: Early observations with Swift-UVOT
  99. Swift-BAT detection of GRB 050410
  100. GRB 050410: Swift XRT Position

Advanced

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