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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"

28046 results found.

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

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