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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').

17828 results found.

  1. XRF 050522: Swift XRT observation
  2. GRB 050520: VLT/ULTRACAM observations
  3. Swift UVOT Observations of GRB 050520
  4. GRB 050520: Swift XRT refined analysis
  5. XRF050509C: Chandra Afterglow Detection
  6. XRF 050509c: Swift XRT Upper Limit
  7. RBO Observations of GRB050520
  8. GRB 050520: TAROT optical limit
  9. GRB 050520: Swift XRT position
  10. No Swift-BAT Lightcurves in real-time for next 3 weeks
  11. Swift-BAT trigger 122203 is not a real GRB
  12. GRB 050504: Swift XRT afterglow candidate has faded
  13. GRB 050509B: Subaru Optical Observations
  14. GRB050502b: Early Observation
  15. Refined Chandra analysis of GRB 050509b
  16. GRB050509b, SDSS pre-burst observations
  17. Chandra observation of GRB 050509b
  18. GRB 050509b: RAPTOR deep, early limits.
  19. GRB050509B: Optical/Infared observations
  20. GRB 050509b: Swift/UVOT follow-up measurements
  21. GRB 050509b Milagro GeV/TeV Observations
  22. GRB050509B: Optical observations at the Very Large Telescope
  23. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  24. GRB 050509a: Swift-BAT refined analysis
  25. GRB 050509B: WSRT Radio Observations
  26. GRB 050505: SARA Observations
  27. Swift UVOT Follow-up Observations of GRB 050509B
  28. GRB 050509B, Optical Observations
  29. GRB 050509B: Swift/XRT refined analysis
  30. GRB050509a: Swift UVOT observations
  31. GRB 050509b: Optical observations
  32. GRB 050509b: Possible Optical Counterpart
  33. GRB 050509A: Optical observations
  34. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  35. GRB 050509b: optical observations
  36. GRB 050509b: Swift XRT Position
  37. GRB 050509B: ROTSE-III Optical Limits
  38. Swift Detection of GRB050509b: A short duration burst
  39. GRB 050509a: Swift XRT Position
  40. Swift Detection of the Burst GRB050509
  41. Swift-BAT detection of GRB 050507
  42. GRB 050505: early time observations
  43. GRB 050505 - Faulkes Telescope North observations
  44. GRB 050502a: Swift XRT Upper Limit
  45. GRB 050505, simultaneous optical observation
  46. GRB 050505: Further Swift UVOT observations.
  47. GRB050416A : 1 GHz limit from GMRT
  48. GRB 050505 UVOT
  49. GRB 050505: Swift XRT Position
  50. GRB050505 Swift-BAT refined analysis
  51. GRB 050416b:Swift XRT afterglow upper limits
  52. GRB 050416b:Swift XRT afterglow upper limits
  53. Swift-BAT detection of GRB050505
  54. GRB 050504: Swift XRT position
  55. Swift UVOT observation of GRB 050504
  56. GRB 050502b, V band Observations
  57. GRB050502B Swift-BAT refined analysis
  58. GRB050502B: I band source in XRT error circle
  59. Swift UVOT refined analysis
  60. Retraction of Swift-BAT trigger 116145
  61. GRB 050502b : optical observation at Lulin observatory
  62. GRB 050502b: Swift XRT Position
  63. GRB050502B: Optical Limits from ANU 1m
  64. Swift Detection of the Bright Burst GRB050502b
  65. GRB050502: ANU 1m optical Observations
  66. Swift-BAT Trigger 115881 is not a real GRB
  67. Swift/BAT possible detection of a weak burst GRB050430
  68. GRB 050401: Rc observation
  69. GRB050416a: Radio Detection
  70. GRB 050422: Swift-UVOT observation
  71. GRB 050422: Swift-BAT refined analysis
  72. GRB 050422: Swift XRT Position
  73. Swift Detection of GRB 050422
  74. GRB 050421: SLOTIS observations
  75. GRB050421: Radio Observations
  76. GRB050421: Radio Observations
  77. GRB 050421: Swift-UVOT observation
  78. GRB 050421: Swift-BAT refined analysis
  79. GRB 050421: ROTSE-III Optical Limits
  80. GRB 050421: early Swift XRT analysis results
  81. GRB 050421: BOOTES-2 simultaneous optical observations
  82. GRB 050421: Optical observations at the INT
  83. Swift Detection of GRB050421
  84. GRB 050416b: Tentative Swift XRT Position
  85. GRB050326: analysis of the XMM-Newton observation
  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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