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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"

21770 results found.

  1. GRB 050416b:Swift XRT afterglow upper limits
  2. GRB 050416b:Swift XRT afterglow upper limits
  3. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  4. GRB050502b: Afterglow Confirmation
  5. GRB050502: P200 Observations (Correction)
  6. GRB050502: P200 Observations
  7. Swift UVOT observation of GRB 050504
  8. GRB050504: P60 Observations
  9. GRB (?) 050504: IR Observations, Intriguing Source
  10. GRB 050502b, Optical observations
  11. GRB050502a: P60 Observations (Correction)
  12. GRB050502a: P60 Observations
  13. Renewal of SGR 1806-20 activity
  14. GRB050502A: Optical Observations
  15. GRB050502B Swift-BAT refined analysis
  16. GRB 050502b: Swift XRT Position
  17. Swift Detection of the Bright Burst GRB050502b
  18. GRB050502: ANU 1m optical Observations
  19. GRB 050502: ROTSE-III Detection of Possible Counterpart
  20. Swift/BAT possible detection of a weak burst GRB050430
  21. GRB050416a: Radio Detection
  22. GRB 050422: Swift-UVOT observation
  23. GRB 050422: Swift XRT Position
  24. Swift Detection of GRB 050422
  25. GRB 050421: SLOTIS observations
  26. GRB 050421: Further Analysis of IR imaging
  27. GRB050421: Radio Observations
  28. GRB050421: Radio Observations
  29. GRB 050421: IR Observations
  30. GRB 050421: ROTSE-III Optical Limits
  31. GRB050421
  32. GRB 050421: early Swift XRT analysis results
  33. GRB 050421: NIR observations
  34. GRB050421: P60 Observations
  35. GRB 050421: BOOTES-2 simultaneous optical observations
  36. Swift Detection of GRB050421
  37. GRB 050416b: Tentative Swift XRT Position
  38. GRB 050315: potential host galaxy
  39. GRB050326: analysis of the XMM-Newton observation
  40. GRB050418: Null Optical Observations
  41. GRB 050412: Chandra observations
  42. GRB050416A, optical observations
  43. GRB 050418: Swift-BAT refined analysis
  44. GRB 050416: Mitsume optical observation
  45. GRB 050416b: LCO observations
  46. GRB 050416b: LCO observations
  47. GRB050416B: IR observations
  48. GRB 050416: Swift/UVOT refined analysis
  49. Swift-BAT detection of GRB 050416b
  50. GRB050412: Radio Observations
  51. GRB 050416: Swift/UVOT detection of afterglow emission
  52. GRB050416: Refined Swift-XRT analysis
  53. GRB 050416,optical observation
  54. GRB050416: P200 NIR Observations
  55. GRB 050416: Swift XRT Position
  56. GRB 050416: Radio observations
  57. Swift BAT/XRT Detection of GRB 050416
  58. GRB 050412: Subaru observations
  59. GRB 050408: RTT150 optical observations
  60. GRB 050412: PROMPT VRcIc Observations
  61. GRB 050408: Kuiper 1.5m observations
  62. GRB 050412: optical observations
  63. GRB 050412: early Swift XRT analysis results
  64. GRB 050412: Swift-BAT refined analysis
  65. GRB 050412: Early Optical/Ultraviolet Observations with
  66. GRB 050408: SDSS Field Calibration
  67. GRB050412: P60 Observations
  68. GRB 050412: Swift XRT Position
  69. GRB050412: ROTSE-III Optical Limits
  70. GRB 050412: IR and Optical observations
  71. GRB 050412: IR Observations
  72. GRB050408: Radio Observations
  73. GRB050410: P60 Observations
  74. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  75. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  76. GRB050410: Radio Observations
  77. GRB050410: MASTER optical observations
  78. GRB 050410: Early observations with Swift-UVOT
  79. GRB 050410: Swift XRT Position
  80. GRB 050408: Inconsistency of host galaxy identification
  81. GRB 050408: Subaru Observations
  82. GRB 050408: WIDGET simultaneous optical observations
  83. GRB 050408: Properties of the Host Galaxy
  84. GRB050408: Radio Observations
  85. GRB 050408: Swift XRT analysis
  86. GRB050408: REM NIR and Optical observation
  87. GRB 050408,optical observation
  88. GRB 050408: Mercator Optical Observations
  89. GRB 050408: Optical afterglow confirmed
  90. GRB 050408: opitcal observation
  91. GRB 050408, optical observations
  92. GRB 050408: Swift XRT Position
  93. GRB 050408: ROTSE-III Optical Limits
  94. GRB050408: MASTER optical observations
  95. GRB050401: Radio Detection
  96. GRB 050406: Magellan optical observations
  97. GRB 050406: early Swift XRT analysis results
  98. GRB 050406 BAT refined analysis
  99. GRB 050406: Early observations with Swift-UVOT
  100. GRB 050406: Swift XRT Position

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