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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"

26352 results found.

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

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