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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"

26484 results found.

  1. Swift Detection of GRB050509b: A short duration burst
  2. Swift Detection of the Burst GRB050509
  3. GRB 050505: early time observations
  4. GRB 050505, simultaneous optical observation
  5. GRB050505: AAVSO observations
  6. GRB050416A : 1 GHz limit from GMRT
  7. GRB050505: Optical Afterglow Candidate
  8. GRB050505 Swift-BAT refined analysis
  9. GRB 050416b:Swift XRT afterglow upper limits
  10. GRB 050416b:Swift XRT afterglow upper limits
  11. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  12. GRB050502b: Afterglow Confirmation
  13. GRB050502: P200 Observations (Correction)
  14. GRB050502: P200 Observations
  15. GRB 050504 : R band observation at Lulin observatory
  16. Swift UVOT observation of GRB 050504
  17. GRB 050504, R band Observations
  18. GRB 050502b, V band Observations
  19. GRB050504: P60 Observations
  20. GRB 050504: A long GRB detected with INTEGRAL
  21. GRB (?) 050504: IR Observations, Intriguing Source
  22. GRB 050502b, Optical observations
  23. GRB050502a: P60 Observations (Correction)
  24. GRB050502a: P60 Observations
  25. Renewal of SGR 1806-20 activity
  26. GRB050502B Swift-BAT refined analysis
  27. Swift UVOT refined analysis
  28. GRB 050502a : R band observation at Lulin observatory
  29. GRB 050502b : optical observation at Lulin observatory
  30. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  31. Swift Detection of the Bright Burst GRB050502b
  32. GRB 050502: INTEGRAL results
  33. GRB 050502: ROTSE-III Detection of Possible Counterpart
  34. Swift/BAT possible detection of a weak burst GRB050430
  35. GRB050416a: Radio Detection
  36. GRB 050422: Swift-UVOT observation
  37. GRB 050422: Swift-BAT refined analysis
  38. Swift Detection of GRB 050422
  39. GRB 050421: SLOTIS observations
  40. GRB 050421: Further Analysis of IR imaging
  41. GRB050421: Radio Observations
  42. GRB050421: Radio Observations
  43. GRB 050421: IR Observations
  44. GRB 050421: Swift-BAT refined analysis
  45. GRB050421
  46. GRB 050421: early Swift XRT analysis results
  47. GRB 050421: NIR observations
  48. GRB050421: P60 Observations
  49. GRB 050421: BOOTES-2 simultaneous optical observations
  50. GRB 050416b: Tentative Swift XRT Position
  51. GRB 050315: potential host galaxy
  52. GRB050326: analysis of the XMM-Newton observation
  53. GRB050418: Null Optical Observations
  54. GRB050416A, optical observations
  55. GRB 050418: Swift-BAT refined analysis
  56. GRB 050416: Mitsume optical observation
  57. GRB050416B: IR observations
  58. GRB050412: Radio Observations
  59. GRB 050416: Swift/UVOT detection of afterglow emission
  60. GRB050416: Refined Swift-XRT analysis
  61. GRB 050416,optical observation
  62. GRB050416: P200 NIR Observations
  63. GRB 050416: Radio observations
  64. Swift BAT/XRT Detection of GRB 050416
  65. GRB 050412: PROMPT VRcIc Observations
  66. GRB 050408: Kuiper 1.5m observations
  67. GRB 050412: early Swift XRT analysis results
  68. GRB 050412: Early Optical/Ultraviolet Observations with
  69. GRB 050408: SDSS Field Calibration
  70. GRB050412: P60 Observations
  71. GRB 050412: Swift XRT Position
  72. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  73. GRB 050412: IR and Optical observations
  74. GRB 050412: IR Observations
  75. GRB050408: Radio Observations
  76. GRB 050401: Optical limit
  77. GRB050410: P60 Observations
  78. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  79. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  80. GRB050410: Radio Observations
  81. GRB050410: MASTER optical observations
  82. GRB 050410: Early observations with Swift-UVOT
  83. Swift-BAT detection of GRB 050410
  84. GRB 050408: Inconsistency of host galaxy identification
  85. GRB 050408: Subaru Observations
  86. GRB 050408: WIDGET simultaneous optical observations
  87. GRB 050408: Properties of the Host Galaxy
  88. GRB050408: Radio Observations
  89. GRB 050408: Swift XRT analysis
  90. GRB 050408: Optical limit at 20 min after the burst
  91. GRB050408: REM NIR and Optical observation
  92. GRB 050408,optical observation
  93. GRB 050408: Mercator Optical Observations
  94. GRB 050408: Optical afterglow confirmed
  95. GRB 050408: opitcal observation
  96. GRB 050408, optical observations
  97. GRB 050408 optical candidate
  98. GRB 050408: Swift XRT Position
  99. GRB050408: MASTER optical observations
  100. GRB050401: Radio Detection

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