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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"

24881 results found.

  1. GRB 050505, simultaneous optical observation
  2. GRB050505: AAVSO observations
  3. GRB050416A : 1 GHz limit from GMRT
  4. GRB050505: Optical Afterglow Candidate
  5. GRB050505 Swift-BAT refined analysis
  6. GRB 050416b:Swift XRT afterglow upper limits
  7. GRB 050416b:Swift XRT afterglow upper limits
  8. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  9. GRB050502b: Afterglow Confirmation
  10. GRB050502: P200 Observations (Correction)
  11. GRB050502: P200 Observations
  12. GRB 050504 : R band observation at Lulin observatory
  13. Swift UVOT observation of GRB 050504
  14. GRB 050504, R band Observations
  15. GRB 050502b, V band Observations
  16. GRB050504: P60 Observations
  17. GRB 050504: A long GRB detected with INTEGRAL
  18. GRB (?) 050504: IR Observations, Intriguing Source
  19. GRB 050502b, Optical observations
  20. GRB050502a: P60 Observations (Correction)
  21. GRB050502a: P60 Observations
  22. Renewal of SGR 1806-20 activity
  23. GRB050502B Swift-BAT refined analysis
  24. Swift UVOT refined analysis
  25. GRB 050502a : R band observation at Lulin observatory
  26. GRB 050502b : optical observation at Lulin observatory
  27. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  28. Swift Detection of the Bright Burst GRB050502b
  29. GRB 050502: INTEGRAL results
  30. GRB 050502: ROTSE-III Detection of Possible Counterpart
  31. Swift/BAT possible detection of a weak burst GRB050430
  32. GRB050416a: Radio Detection
  33. GRB 050422: Swift-UVOT observation
  34. GRB 050422: Swift-BAT refined analysis
  35. Swift Detection of GRB 050422
  36. GRB 050421: SLOTIS observations
  37. GRB 050421: Further Analysis of IR imaging
  38. GRB050421: Radio Observations
  39. GRB050421: Radio Observations
  40. GRB 050421: IR Observations
  41. GRB 050421: Swift-BAT refined analysis
  42. GRB050421
  43. GRB 050421: early Swift XRT analysis results
  44. GRB 050421: NIR observations
  45. GRB050421: P60 Observations
  46. GRB 050421: BOOTES-2 simultaneous optical observations
  47. GRB 050416b: Tentative Swift XRT Position
  48. GRB 050315: potential host galaxy
  49. GRB050326: analysis of the XMM-Newton observation
  50. GRB050418: Null Optical Observations
  51. GRB050416A, optical observations
  52. GRB 050418: Swift-BAT refined analysis
  53. GRB 050416: Mitsume optical observation
  54. GRB050416B: IR observations
  55. GRB050412: Radio Observations
  56. GRB 050416: Swift/UVOT detection of afterglow emission
  57. GRB050416: Refined Swift-XRT analysis
  58. GRB 050416,optical observation
  59. GRB050416: P200 NIR Observations
  60. GRB 050416: Radio observations
  61. Swift BAT/XRT Detection of GRB 050416
  62. GRB 050412: PROMPT VRcIc Observations
  63. GRB 050408: Kuiper 1.5m observations
  64. GRB 050412: early Swift XRT analysis results
  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. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  70. GRB 050412: IR and Optical observations
  71. GRB 050412: IR Observations
  72. GRB050408: Radio Observations
  73. GRB 050401: Optical limit
  74. GRB050410: P60 Observations
  75. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  76. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  77. GRB050410: Radio Observations
  78. GRB050410: MASTER optical observations
  79. GRB 050410: Early observations with Swift-UVOT
  80. Swift-BAT detection of GRB 050410
  81. GRB 050408: Inconsistency of host galaxy identification
  82. GRB 050408: Subaru Observations
  83. GRB 050408: WIDGET simultaneous optical observations
  84. GRB 050408: Properties of the Host Galaxy
  85. GRB050408: Radio Observations
  86. GRB 050408: Swift XRT analysis
  87. GRB 050408: Optical limit at 20 min after the burst
  88. GRB050408: REM NIR and Optical observation
  89. GRB 050408,optical observation
  90. GRB 050408: Mercator Optical Observations
  91. GRB 050408: Optical afterglow confirmed
  92. GRB 050408: opitcal observation
  93. GRB 050408, optical observations
  94. GRB 050408 optical candidate
  95. GRB 050408: Swift XRT Position
  96. GRB050408: MASTER optical observations
  97. GRB050401: Radio Detection
  98. GRB 050406: early Swift XRT analysis results
  99. GRB 050406 BAT refined analysis
  100. GRB 050406: Early observations with Swift-UVOT

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