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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"

28049 results found.

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

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