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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"

20958 results found.

  1. GRB050505: AAVSO observations
  2. GRB 050505 UVOT
  3. GRB050505: Optical Afterglow Candidate
  4. GRB050505 Swift-BAT refined analysis
  5. GRB 050502a: Optical Observations
  6. GRB 050416b:Swift XRT afterglow upper limits
  7. GRB 050416b:Swift XRT afterglow upper limits
  8. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  9. GRB050502b: Afterglow Confirmation
  10. GRB050502: P200 Observations (Correction)
  11. GRB050502: P200 Observations
  12. GRB 050504 : R band observation at Lulin observatory
  13. GRB 050504, R band Observations
  14. GRB050504: Faulkes North optical robotic limit
  15. GRB 050502b, V band Observations
  16. GRB050504: P60 Observations
  17. GRB (?) 050504: IR Observations, Intriguing Source
  18. GRB 050502b, Optical observations
  19. GRB050502a: P60 Observations (Correction)
  20. GRB050502a: P60 Observations
  21. GRB 050502a: RBO Observations
  22. GRB 050502A: WSRT Radio Observations
  23. GRB050502A: Optical Observations
  24. GRB050502B Swift-BAT refined analysis
  25. GRB 050502b : optical observation at Lulin observatory
  26. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  27. Swift Detection of the Bright Burst GRB050502b
  28. GRB050502: ANU 1m optical Observations
  29. GRB 050502: Confirmed variability of the afterglow candidate +
  30. GRB 050502: PAIRITEL IR Observations
  31. GRB 050502: ROTSE-III Detection of Possible Counterpart
  32. Swift/BAT possible detection of a weak burst GRB050430
  33. GRB050416a: Radio Detection
  34. Swift Detection of GRB 050422
  35. GRB 050421: NIR observations
  36. GRB 050416: Optical/NIR observations
  37. GRB 050421: SLOTIS observations
  38. GRB 050421: Further Analysis of IR imaging
  39. GRB050421: Radio Observations
  40. GRB050421: Radio Observations
  41. GRB 050421: IR Observations
  42. GRB 050421: ROTSE-III Optical Limits
  43. GRB 050421: NIR observations re-examination
  44. GRB 050421: NIR observations
  45. GRB050421: P60 Observations
  46. GRB 050421: BOOTES-2 simultaneous optical observations
  47. GRB 050421: Optical observations at the INT
  48. Swift Detection of GRB050421
  49. GRB 050416b: Tentative Swift XRT Position
  50. GRB 050315: potential host galaxy
  51. GRB050418: Null Optical Observations
  52. GRB 050412: Chandra observations
  53. GRB050416A, optical observations
  54. GRB 050416 : optical observation at Xinglong observatory
  55. GRB 050416B: optical observations
  56. GRB 050416b: LCO observations
  57. GRB 050416b: LCO observations
  58. GRB050416B: IR observations
  59. GRB050412: Radio Observations
  60. GRB 050416: Swift/UVOT detection of afterglow emission
  61. GRB050416: Maidanak optical observations
  62. GRB 050416: ART observations
  63. GRB 050416: KAIT observations
  64. GRB050416: P200 NIR Observations
  65. GRB 050416: Radio observations
  66. GRB 050412: Subaru observations
  67. GRB 050408: RTT150 optical observations
  68. GRB 050412: PROMPT VRcIc Observations
  69. GRB 050408: Kuiper 1.5m observations
  70. GRB 050412: optical observations
  71. GRB 050408: refined XRT analysis, no jet break seen yet
  72. GRB 050412: ANU 2.3m observations
  73. GRB 050412: Early Optical/Ultraviolet Observations with
  74. GRB 050412: LCO Optical Observations
  75. GRB 050412: Optical observations
  76. GRB050412: P60 Observations
  77. GRB 050412: LCO optical observations
  78. GRB 050412: IR and Optical observations
  79. GRB 050412: IR Observations
  80. GRB050408: Radio Observations
  81. GRB050410: P60 Observations
  82. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  83. GRB 050410, optical observations
  84. GRB 050408: PROMPT VRcIc Observations
  85. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  86. GRB 050410 R band Optical Observations
  87. GRB 050410, optical observations
  88. GRB050410: Radio Observations
  89. GRB 050408: Swift XRT measurement of possible jet break
  90. GRB050410: MASTER optical observations
  91. GRB 050410: Early observations with Swift-UVOT
  92. Swift-BAT detection of GRB 050410
  93. GRB 050408: Subaru Observations
  94. GRB 050408: WIDGET simultaneous optical observations
  95. GRB 050408: SOAR UBVRc Observations
  96. GRB 050408: Properties of the Host Galaxy
  97. GRB 050408: Mercator Optical Observations
  98. GRB050408: Radio Observations
  99. GRB 050408, SMARTS optical/IR afterglow observations
  100. GRB 050408, optical observations

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