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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"

20365 results found.

  1. GRB 050509c: ROTSE-III Optical Limits
  2. GRB 050505, early TAROT observation
  3. GRB050509c: REM NIR and Optical observations
  4. GRB 050505: SARA Observations
  5. GRB 050509B, Optical Observations
  6. GRB 050509b: Possible Optical Counterpart
  7. GRB 050509A: Optical observations
  8. GRB050509b: Radio Observations
  9. Swift Detection of GRB050509b: A short duration burst
  10. Swift Detection of the Burst GRB050509
  11. Swift-BAT detection of GRB 050507
  12. GRB 050502a: Swift XRT Upper Limit
  13. GRB 050505, simultaneous optical observation
  14. GRB050505: AAVSO observations
  15. GRB050416A : 1 GHz limit from GMRT
  16. GRB050505: Optical Afterglow Candidate
  17. GRB 050416b:Swift XRT afterglow upper limits
  18. GRB 050416b:Swift XRT afterglow upper limits
  19. Swift-BAT detection of GRB050505
  20. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  21. GRB050502b: Afterglow Confirmation
  22. GRB050502: P200 Observations (Correction)
  23. GRB050502: P200 Observations
  24. Swift UVOT observation of GRB 050504
  25. GRB050504: P60 Observations
  26. GRB 050504: A long GRB detected with INTEGRAL
  27. GRB (?) 050504: IR Observations, Intriguing Source
  28. GRB 050502b, Optical observations
  29. GRB050502a: P60 Observations (Correction)
  30. GRB050502a: P60 Observations
  31. GRB050502A: Optical Observations
  32. GRB050502B Swift-BAT refined analysis
  33. Swift Detection of the Bright Burst GRB050502b
  34. GRB 050502: ROTSE-III Detection of Possible Counterpart
  35. Swift/BAT possible detection of a weak burst GRB050430
  36. GRB050416a: Radio Detection
  37. Swift Detection of GRB 050422
  38. GRB 050421: SLOTIS observations
  39. GRB 050421: Further Analysis of IR imaging
  40. GRB050421: Radio Observations
  41. GRB050421: Radio Observations
  42. GRB 050421: IR Observations
  43. GRB050421
  44. GRB 050421: early Swift XRT analysis results
  45. GRB 050421: NIR observations
  46. GRB050421: P60 Observations
  47. GRB 050421: BOOTES-2 simultaneous optical observations
  48. Swift Detection of GRB050421
  49. GRB 050416b: Tentative Swift XRT Position
  50. GRB 050315: potential host galaxy
  51. GRB050326: analysis of the XMM-Newton observation
  52. GRB050418: Null Optical Observations
  53. GRB 050412: Chandra observations
  54. GRB050416A, optical observations
  55. GRB 050416: Mitsume optical observation
  56. GRB 050416 : optical observation at Xinglong observatory
  57. GRB050416B: IR observations
  58. GRB050412: Radio Observations
  59. GRB 050416: Swift/UVOT detection of afterglow emission
  60. GRB 050416,optical observation
  61. GRB050416: P200 NIR Observations
  62. GRB 050416: Radio observations
  63. Swift BAT/XRT Detection of GRB 050416
  64. GRB 050408: Kuiper 1.5m observations
  65. GRB 050412: Early Optical/Ultraviolet Observations with
  66. GRB 050408: SDSS Field Calibration
  67. GRB050412: P60 Observations
  68. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  69. GRB 050412: IR and Optical observations
  70. GRB 050412: IR Observations
  71. GRB050408: Radio Observations
  72. GRB050410: P60 Observations
  73. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  74. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  75. GRB 050410 R band Optical Observations
  76. GRB050410: Radio Observations
  77. GRB050410: MASTER optical observations
  78. GRB 050410: Early observations with Swift-UVOT
  79. GRB 050408: Inconsistency of host galaxy identification
  80. GRB 050408: Subaru Observations
  81. GRB 050408: WIDGET simultaneous optical observations
  82. GRB 050408: Properties of the Host Galaxy
  83. GRB050408: Radio Observations
  84. GRB050408: REM NIR and Optical observation
  85. GRB 050408,optical observation
  86. GRB 050408: Optical afterglow confirmed
  87. GRB 050408: opitcal observation
  88. GRB 050408, optical observations
  89. GRB 050408: Swift XRT Position
  90. GRB050408: MASTER optical observations
  91. GRB050401: Radio Detection
  92. GRB 050406: Early observations with Swift-UVOT
  93. Swift-BAT detection of GRB 050406
  94. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  95. GRB 050401 BAT refined analysis
  96. GRB050401: TNG R-band observation
  97. GRB 050402: Early observations with Swift-UVOT
  98. Swift Trigger 113225: P60 Observations
  99. GRB 050401: Optical afterglow confirmed
  100. GRB050331: No Afterglow Detected

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