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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"

24887 results found.

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

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