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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"

21455 results found.

  1. GRB050509b, SDSS pre-burst observations
  2. GRB 050509b: Keck/Chandra Cross-Correlation
  3. GRB 050509b: Keck/Chandra Cross-Correlation
  4. Chandra observation of GRB 050509b
  5. GRB 050509b: RAPTOR deep, early limits.
  6. GRB050509B: Optical/Infared observations
  7. GRB 050509b: Swift/UVOT follow-up measurements
  8. GRB 050509b Milagro GeV/TeV Observations
  9. GRB050509B: Optical observations at the Very Large Telescope
  10. GRB 050509b: No Optical Variability in XRT Error Circle
  11. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  12. GRB 050509a: Swift-BAT refined analysis
  13. GRB 050509B: WSRT Radio Observations
  14. GRB 050505: SARA Observations
  15. Swift UVOT Follow-up Observations of GRB 050509B
  16. GRB 050509B, Optical Observations
  17. GRB 050509B: Swift/XRT refined analysis
  18. GRB050509a: Swift UVOT observations
  19. GRB 050509b: Optical observations
  20. GRB 050509b: Precision Astrometry
  21. GRB 050509b: Possible Optical Counterpart
  22. GRB 050509A: Optical observations
  23. GRB 050509b: Optical Counterpart Candidate
  24. GRB050509b: Radio Observations
  25. GRB 050509b: PAIRITEL and WIYN Observations
  26. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  27. GRB 050509b: optical observations
  28. GRB 050509b: Swift XRT Position
  29. GRB 050509B: ROTSE-III Optical Limits
  30. Swift Detection of GRB050509b: A short duration burst
  31. GRB 050509a: Swift XRT Position
  32. Swift Detection of the Burst GRB050509
  33. Swift-BAT detection of GRB 050507
  34. GRB 050505: early time observations
  35. GRB 050505 - Faulkes Telescope North observations
  36. GRB 050502a: Swift XRT Upper Limit
  37. GRB 050505, simultaneous optical observation
  38. GRB 050505: Further Swift UVOT observations.
  39. GRB050416A : 1 GHz limit from GMRT
  40. GRB 050505 UVOT
  41. GRB050505: Optical Afterglow Candidate
  42. GRB 050505: Swift XRT Position
  43. GRB050505 Swift-BAT refined analysis
  44. GRB 050416b:Swift XRT afterglow upper limits
  45. GRB 050416b:Swift XRT afterglow upper limits
  46. Swift-BAT detection of GRB050505
  47. GRB 050504: Swift XRT position
  48. Swift UVOT observation of GRB 050504
  49. GRB 050502b, V band Observations
  50. GRB050502B Swift-BAT refined analysis
  51. GRB050502B: I band source in XRT error circle
  52. Swift UVOT refined analysis
  53. Retraction of Swift-BAT trigger 116145
  54. GRB 050502b : optical observation at Lulin observatory
  55. GRB 050502b: Swift XRT Position
  56. GRB050502B: Optical Limits from ANU 1m
  57. Swift Detection of the Bright Burst GRB050502b
  58. GRB050502: ANU 1m optical Observations
  59. Swift-BAT Trigger 115881 is not a real GRB
  60. Swift/BAT possible detection of a weak burst GRB050430
  61. GRB 050401: Rc observation
  62. GRB050416a: Radio Detection
  63. GRB 050422: Swift-UVOT observation
  64. GRB 050422: Swift-BAT refined analysis
  65. GRB 050422: Swift XRT Position
  66. Swift Detection of GRB 050422
  67. GRB 050421: NIR observations
  68. GRB 050421: SLOTIS observations
  69. GRB 050421: Further Analysis of IR imaging
  70. GRB050421: Radio Observations
  71. GRB050421: Radio Observations
  72. GRB 050421: Swift-UVOT observation
  73. GRB 050421: IR Observations
  74. GRB 050421: Swift-BAT refined analysis
  75. GRB 050421: ROTSE-III Optical Limits
  76. GRB 050421: NIR observations re-examination
  77. GRB 050421: early Swift XRT analysis results
  78. GRB 050421: NIR observations
  79. GRB050421: P60 Observations
  80. GRB 050421: BOOTES-2 simultaneous optical observations
  81. GRB 050421: Optical observations at the INT
  82. Swift Detection of GRB050421
  83. GRB 050416b: Tentative Swift XRT Position
  84. GRB050326: analysis of the XMM-Newton observation
  85. GRB 050412: Chandra observations
  86. GRB 050418: Swift-BAT refined analysis
  87. Swift-BAT detection of the bright and long GRB 050418
  88. GRB 050416B: optical observations
  89. GRB 050416b: Swift-BAT refined analysis
  90. GRB 050416: Swift/UVOT refined analysis
  91. Swift-BAT detection of GRB 050416b
  92. GRB050412: Radio Observations
  93. GRB 050416: Swift/UVOT detection of afterglow emission
  94. GRB050416: Refined Swift-XRT analysis
  95. GRB050416: Maidanak optical observations
  96. GRB 050416: Swift-BAT refined analysis
  97. GRB 050416,optical observation
  98. GRB 050416: KAIT observations
  99. GRB 050416: Swift XRT Position
  100. GRB 050416: Radio observations

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