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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"

28089 results found.

  1. GRB 050509b: Optical observations
  2. GRB 050509A: Optical observations
  3. GRB050509b: Radio Observations
  4. GRB 050509b: PAIRITEL and WIYN Observations
  5. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  6. Swift Detection of GRB050509b: A short duration burst
  7. Swift Detection of the Burst GRB050509
  8. GRB 050505: early time observations
  9. GRB 050505, simultaneous optical observation
  10. GRB050505: AAVSO observations
  11. GRB050416A : 1 GHz limit from GMRT
  12. GRB050505: Optical Afterglow Candidate
  13. GRB050505 Swift-BAT refined analysis
  14. GRB 050416b:Swift XRT afterglow upper limits
  15. GRB 050416b:Swift XRT afterglow upper limits
  16. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  17. GRB050502b: Afterglow Confirmation
  18. GRB050502: P200 Observations (Correction)
  19. GRB050502: P200 Observations
  20. GRB 050504 : R band observation at Lulin observatory
  21. Swift UVOT observation of GRB 050504
  22. GRB 050504, R band Observations
  23. GRB 050502b, V band Observations
  24. GRB050504: P60 Observations
  25. GRB 050504: A long GRB detected with INTEGRAL
  26. GRB (?) 050504: IR Observations, Intriguing Source
  27. GRB 050502b, Optical observations
  28. GRB050502a: P60 Observations (Correction)
  29. GRB050502a: P60 Observations
  30. Renewal of SGR 1806-20 activity
  31. GRB050502B Swift-BAT refined analysis
  32. Swift UVOT refined analysis
  33. GRB 050502a : R band observation at Lulin observatory
  34. GRB 050502b : optical observation at Lulin observatory
  35. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  36. Swift Detection of the Bright Burst GRB050502b
  37. GRB 050502: INTEGRAL results
  38. GRB 050502: ROTSE-III Detection of Possible Counterpart
  39. Swift/BAT possible detection of a weak burst GRB050430
  40. GRB050416a: Radio Detection
  41. GRB 050422: Swift-UVOT observation
  42. GRB 050422: Swift-BAT refined analysis
  43. Swift Detection of GRB 050422
  44. GRB 050421: SLOTIS observations
  45. GRB 050421: Further Analysis of IR imaging
  46. GRB050421: Radio Observations
  47. GRB050421: Radio Observations
  48. GRB 050421: IR Observations
  49. GRB 050421: Swift-BAT refined analysis
  50. GRB050421
  51. GRB 050421: early Swift XRT analysis results
  52. GRB 050421: NIR observations
  53. GRB050421: P60 Observations
  54. GRB 050421: BOOTES-2 simultaneous optical observations
  55. GRB 050416b: Tentative Swift XRT Position
  56. GRB 050315: potential host galaxy
  57. GRB050326: analysis of the XMM-Newton observation
  58. GRB050418: Null Optical Observations
  59. GRB050416A, optical observations
  60. GRB 050418: Swift-BAT refined analysis
  61. GRB 050416: Mitsume optical observation
  62. GRB050416B: IR observations
  63. GRB050412: Radio Observations
  64. GRB 050416: Swift/UVOT detection of afterglow emission
  65. GRB050416: Refined Swift-XRT analysis
  66. GRB 050416,optical observation
  67. GRB050416: P200 NIR Observations
  68. GRB 050416: Radio observations
  69. Swift BAT/XRT Detection of GRB 050416
  70. GRB 050412: PROMPT VRcIc Observations
  71. GRB 050408: Kuiper 1.5m observations
  72. GRB 050412: early Swift XRT analysis results
  73. GRB 050412: Early Optical/Ultraviolet Observations with
  74. GRB 050408: SDSS Field Calibration
  75. GRB050412: P60 Observations
  76. GRB 050412: Swift XRT Position
  77. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  78. GRB 050412: IR and Optical observations
  79. GRB 050412: IR Observations
  80. GRB050408: Radio Observations
  81. GRB 050401: Optical limit
  82. GRB050410: P60 Observations
  83. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  84. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  85. GRB050410: Radio Observations
  86. GRB050410: MASTER optical observations
  87. GRB 050410: Early observations with Swift-UVOT
  88. Swift-BAT detection of GRB 050410
  89. GRB 050408: Inconsistency of host galaxy identification
  90. GRB 050408: Subaru Observations
  91. GRB 050408: WIDGET simultaneous optical observations
  92. GRB 050408: Properties of the Host Galaxy
  93. GRB050408: Radio Observations
  94. GRB 050408: Swift XRT analysis
  95. GRB 050408: Optical limit at 20 min after the burst
  96. GRB050408: REM NIR and Optical observation
  97. GRB 050408,optical observation
  98. GRB 050408: Mercator Optical Observations
  99. GRB 050408: Optical afterglow confirmed
  100. GRB 050408: opitcal observation

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