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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"

28090 results found.

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

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