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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"

27392 results found.

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

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