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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"

27391 results found.

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

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