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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"

20538 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. GRB 050509b: optical observations
  5. GRB 050509b: Swift XRT Position
  6. Swift Detection of GRB050509b: A short duration burst
  7. Swift Detection of the Burst GRB050509
  8. GRB 050505: early time observations
  9. GRB 050505 - Faulkes Telescope North observations
  10. GRB 050502a: Swift XRT Upper Limit
  11. GRB050505: Infrared observations
  12. GRB 050505: Further Swift UVOT observations.
  13. GRB050505: AAVSO observations
  14. GRB 050505 UVOT
  15. GRB050505: Optical Afterglow Candidate
  16. GRB050505 Swift-BAT refined analysis
  17. GRB 050502a: Optical Observations
  18. GRB 050416b:Swift XRT afterglow upper limits
  19. GRB 050416b:Swift XRT afterglow upper limits
  20. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  21. GRB050502b: Afterglow Confirmation
  22. GRB050502: P200 Observations (Correction)
  23. GRB050502: P200 Observations
  24. GRB 050504 : R band observation at Lulin observatory
  25. GRB 050504, R band Observations
  26. GRB050504: Faulkes North optical robotic limit
  27. GRB 050502b, V band Observations
  28. GRB050504: P60 Observations
  29. GRB (?) 050504: IR Observations, Intriguing Source
  30. GRB 050502b, Optical observations
  31. GRB050502a: P60 Observations (Correction)
  32. GRB050502a: P60 Observations
  33. GRB 050502a: RBO Observations
  34. GRB 050502A: WSRT Radio Observations
  35. GRB050502A: Optical Observations
  36. GRB050502B Swift-BAT refined analysis
  37. GRB 050502b : optical observation at Lulin observatory
  38. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  39. Swift Detection of the Bright Burst GRB050502b
  40. GRB050502: ANU 1m optical Observations
  41. GRB 050502: PAIRITEL IR Observations
  42. GRB 050502: ROTSE-III Detection of Possible Counterpart
  43. Swift/BAT possible detection of a weak burst GRB050430
  44. GRB050416a: Radio Detection
  45. Swift Detection of GRB 050422
  46. GRB 050421: NIR observations
  47. GRB 050416: Optical/NIR observations
  48. GRB 050421: SLOTIS observations
  49. GRB 050421: Further Analysis of IR imaging
  50. GRB050421: Radio Observations
  51. GRB050421: Radio Observations
  52. GRB 050421: IR Observations
  53. GRB 050421: ROTSE-III Optical Limits
  54. GRB 050421: NIR observations re-examination
  55. GRB 050421: NIR observations
  56. GRB050421: P60 Observations
  57. GRB 050421: BOOTES-2 simultaneous optical observations
  58. GRB 050421: Optical observations at the INT
  59. Swift Detection of GRB050421
  60. GRB 050416b: Tentative Swift XRT Position
  61. GRB 050315: potential host galaxy
  62. GRB050418: Null Optical Observations
  63. GRB 050412: Chandra observations
  64. GRB050416A, optical observations
  65. GRB 050416 : optical observation at Xinglong observatory
  66. GRB 050416B: optical observations
  67. GRB 050416b: LCO observations
  68. GRB 050416b: LCO observations
  69. GRB050416B: IR observations
  70. GRB050412: Radio Observations
  71. GRB 050416: Swift/UVOT detection of afterglow emission
  72. GRB050416: Maidanak optical observations
  73. GRB 050416: ART observations
  74. GRB 050416: KAIT observations
  75. GRB050416: P200 NIR Observations
  76. GRB 050416: Radio observations
  77. GRB 050412: Subaru observations
  78. GRB 050408: RTT150 optical observations
  79. GRB 050412: PROMPT VRcIc Observations
  80. GRB 050408: Kuiper 1.5m observations
  81. GRB 050412: optical observations
  82. GRB 050408: refined XRT analysis, no jet break seen yet
  83. GRB 050412: ANU 2.3m observations
  84. GRB 050412: Early Optical/Ultraviolet Observations with
  85. GRB 050408: SDSS Field Calibration
  86. GRB 050412: LCO Optical Observations
  87. GRB 050412: Optical observations
  88. GRB050412: P60 Observations
  89. GRB 050412: LCO optical observations
  90. GRB 050412: IR and Optical observations
  91. GRB 050412: IR Observations
  92. GRB050408: Radio Observations
  93. GRB050410: P60 Observations
  94. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  95. GRB 050410, optical observations
  96. GRB 050408: PROMPT VRcIc Observations
  97. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  98. GRB 050410 R band Optical Observations
  99. GRB 050410, optical observations
  100. GRB050410: Radio Observations

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