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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"

28088 results found.

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

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