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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"

19858 results found.

  1. GRB050509b: Radio Observations
  2. Swift Detection of GRB050509b: A short duration burst
  3. Swift Detection of the Burst GRB050509
  4. Swift-BAT detection of GRB 050507
  5. GRB 050502a: Swift XRT Upper Limit
  6. GRB 050505, simultaneous optical observation
  7. GRB050505: AAVSO observations
  8. GRB050416A : 1 GHz limit from GMRT
  9. GRB050505: Optical Afterglow Candidate
  10. GRB 050416b:Swift XRT afterglow upper limits
  11. GRB 050416b:Swift XRT afterglow upper limits
  12. Swift-BAT detection of GRB050505
  13. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  14. GRB050502b: Afterglow Confirmation
  15. GRB050502: P200 Observations (Correction)
  16. GRB050502: P200 Observations
  17. Swift UVOT observation of GRB 050504
  18. GRB050504: P60 Observations
  19. GRB 050504: A long GRB detected with INTEGRAL
  20. GRB (?) 050504: IR Observations, Intriguing Source
  21. GRB 050502b, Optical observations
  22. GRB050502a: P60 Observations (Correction)
  23. GRB050502a: P60 Observations
  24. GRB050502A: Optical Observations
  25. GRB050502B Swift-BAT refined analysis
  26. Swift Detection of the Bright Burst GRB050502b
  27. GRB 050502: ROTSE-III Detection of Possible Counterpart
  28. Swift/BAT possible detection of a weak burst GRB050430
  29. GRB050416a: Radio Detection
  30. Swift Detection of GRB 050422
  31. GRB 050421: SLOTIS observations
  32. GRB 050421: Further Analysis of IR imaging
  33. GRB050421: Radio Observations
  34. GRB050421: Radio Observations
  35. GRB 050421: IR Observations
  36. GRB050421
  37. GRB 050421: early Swift XRT analysis results
  38. GRB 050421: NIR observations
  39. GRB050421: P60 Observations
  40. GRB 050421: BOOTES-2 simultaneous optical observations
  41. Swift Detection of GRB050421
  42. GRB 050416b: Tentative Swift XRT Position
  43. GRB 050315: potential host galaxy
  44. GRB050326: analysis of the XMM-Newton observation
  45. GRB050418: Null Optical Observations
  46. GRB 050412: Chandra observations
  47. GRB050416A, optical observations
  48. GRB 050416: Mitsume optical observation
  49. GRB 050416 : optical observation at Xinglong observatory
  50. GRB050416B: IR observations
  51. GRB050412: Radio Observations
  52. GRB 050416: Swift/UVOT detection of afterglow emission
  53. GRB 050416,optical observation
  54. GRB050416: P200 NIR Observations
  55. GRB 050416: Radio observations
  56. Swift BAT/XRT Detection of GRB 050416
  57. GRB 050408: Kuiper 1.5m observations
  58. GRB 050412: Early Optical/Ultraviolet Observations with
  59. GRB 050408: SDSS Field Calibration
  60. GRB050412: P60 Observations
  61. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  62. GRB 050412: IR and Optical observations
  63. GRB 050412: IR Observations
  64. GRB050408: Radio Observations
  65. GRB050410: P60 Observations
  66. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  67. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  68. GRB 050410 R band Optical Observations
  69. GRB050410: Radio Observations
  70. GRB050410: MASTER optical observations
  71. GRB 050410: Early observations with Swift-UVOT
  72. GRB 050408: Inconsistency of host galaxy identification
  73. GRB 050408: Subaru Observations
  74. GRB 050408: WIDGET simultaneous optical observations
  75. GRB 050408: Properties of the Host Galaxy
  76. GRB050408: Radio Observations
  77. GRB050408: REM NIR and Optical observation
  78. GRB 050408,optical observation
  79. GRB 050408: Optical afterglow confirmed
  80. GRB 050408: opitcal observation
  81. GRB 050408, optical observations
  82. GRB 050408: Swift XRT Position
  83. GRB050408: MASTER optical observations
  84. GRB050401: Radio Detection
  85. GRB 050406: Early observations with Swift-UVOT
  86. Swift-BAT detection of GRB 050406
  87. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  88. GRB 050401 BAT refined analysis
  89. GRB050401: TNG R-band observation
  90. GRB 050402: Early observations with Swift-UVOT
  91. Swift Trigger 113225: P60 Observations
  92. GRB 050401: Optical afterglow confirmed
  93. GRB050331: No Afterglow Detected
  94. GRB 050331: Swift UVOT Source
  95. GRB 050326: Early observations with Swift-UVOT
  96. GRB 050326 XMM-Newton observation
  97. GRB 050326: Swift XRT Position
  98. GRB050326: delayed XRT observation
  99. GRB050319: optical observation, March 20-22
  100. GRB050319: RTT150 Optical Observations

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