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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"

20355 results found.

  1. Swift-BAT detection of GRB 050507
  2. GRB 050502a: Swift XRT Upper Limit
  3. GRB 050505, simultaneous optical observation
  4. GRB050505: AAVSO observations
  5. GRB050416A : 1 GHz limit from GMRT
  6. GRB050505: Optical Afterglow Candidate
  7. GRB 050416b:Swift XRT afterglow upper limits
  8. GRB 050416b:Swift XRT afterglow upper limits
  9. Swift-BAT detection of GRB050505
  10. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  11. GRB050502b: Afterglow Confirmation
  12. GRB050502: P200 Observations (Correction)
  13. GRB050502: P200 Observations
  14. Swift UVOT observation of GRB 050504
  15. GRB050504: P60 Observations
  16. GRB 050504: A long GRB detected with INTEGRAL
  17. GRB (?) 050504: IR Observations, Intriguing Source
  18. GRB 050502b, Optical observations
  19. GRB050502a: P60 Observations (Correction)
  20. GRB050502a: P60 Observations
  21. GRB050502A: Optical Observations
  22. GRB050502B Swift-BAT refined analysis
  23. Swift Detection of the Bright Burst GRB050502b
  24. GRB 050502: ROTSE-III Detection of Possible Counterpart
  25. Swift/BAT possible detection of a weak burst GRB050430
  26. GRB050416a: Radio Detection
  27. Swift Detection of GRB 050422
  28. GRB 050421: SLOTIS observations
  29. GRB 050421: Further Analysis of IR imaging
  30. GRB050421: Radio Observations
  31. GRB050421: Radio Observations
  32. GRB 050421: IR Observations
  33. GRB050421
  34. GRB 050421: early Swift XRT analysis results
  35. GRB 050421: NIR observations
  36. GRB050421: P60 Observations
  37. GRB 050421: BOOTES-2 simultaneous optical observations
  38. Swift Detection of GRB050421
  39. GRB 050416b: Tentative Swift XRT Position
  40. GRB 050315: potential host galaxy
  41. GRB050326: analysis of the XMM-Newton observation
  42. GRB050418: Null Optical Observations
  43. GRB 050412: Chandra observations
  44. GRB050416A, optical observations
  45. GRB 050416: Mitsume optical observation
  46. GRB 050416 : optical observation at Xinglong observatory
  47. GRB050416B: IR observations
  48. GRB050412: Radio Observations
  49. GRB 050416: Swift/UVOT detection of afterglow emission
  50. GRB 050416,optical observation
  51. GRB050416: P200 NIR Observations
  52. GRB 050416: Radio observations
  53. Swift BAT/XRT Detection of GRB 050416
  54. GRB 050408: Kuiper 1.5m observations
  55. GRB 050412: Early Optical/Ultraviolet Observations with
  56. GRB 050408: SDSS Field Calibration
  57. GRB050412: P60 Observations
  58. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  59. GRB 050412: IR and Optical observations
  60. GRB 050412: IR Observations
  61. GRB050408: Radio Observations
  62. GRB050410: P60 Observations
  63. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  64. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  65. GRB 050410 R band Optical Observations
  66. GRB050410: Radio Observations
  67. GRB050410: MASTER optical observations
  68. GRB 050410: Early observations with Swift-UVOT
  69. GRB 050408: Inconsistency of host galaxy identification
  70. GRB 050408: Subaru Observations
  71. GRB 050408: WIDGET simultaneous optical observations
  72. GRB 050408: Properties of the Host Galaxy
  73. GRB050408: Radio Observations
  74. GRB050408: REM NIR and Optical observation
  75. GRB 050408,optical observation
  76. GRB 050408: Optical afterglow confirmed
  77. GRB 050408: opitcal observation
  78. GRB 050408, optical observations
  79. GRB 050408: Swift XRT Position
  80. GRB050408: MASTER optical observations
  81. GRB050401: Radio Detection
  82. GRB 050406: Early observations with Swift-UVOT
  83. Swift-BAT detection of GRB 050406
  84. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  85. GRB 050401 BAT refined analysis
  86. GRB050401: TNG R-band observation
  87. GRB 050402: Early observations with Swift-UVOT
  88. Swift Trigger 113225: P60 Observations
  89. GRB 050401: Optical afterglow confirmed
  90. GRB050331: No Afterglow Detected
  91. GRB 050331: Swift UVOT Source
  92. GRB 050326: Early observations with Swift-UVOT
  93. GRB 050326 XMM-Newton observation
  94. GRB 050326: Swift XRT Position
  95. GRB050326: delayed XRT observation
  96. GRB050319: optical observation, March 20-22
  97. GRB050319: RTT150 Optical Observations
  98. GRB050319: VLA Observations
  99. GRB050319: radio observation
  100. GRB 050319: Swift-UVOT detection of the afterglow

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