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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"

19128 results found.

  1. RBO Observations of GRB050522
  2. XRF 050522: Swift XRT observation
  3. GRB 050520: VLT/ULTRACAM observations
  4. Swift UVOT Observations of GRB 050520
  5. GRB 050520: Swift XRT refined analysis
  6. XRF050509C: Chandra Afterglow Detection
  7. XRF 050509c: Swift XRT Upper Limit
  8. RBO Observations of GRB050520
  9. GRB 050520: TAROT optical limit
  10. GRB 050520: Swift XRT position
  11. No Swift-BAT Lightcurves in real-time for next 3 weeks
  12. Swift-BAT trigger 122203 is not a real GRB
  13. GRB 050504: Swift XRT afterglow candidate has faded
  14. GRB 050509B: Subaru Optical Observations
  15. GRB050502b: Early Observation
  16. Refined Chandra analysis of GRB 050509b
  17. GRB050509b, SDSS pre-burst observations
  18. Chandra observation of GRB 050509b
  19. GRB 050509b: RAPTOR deep, early limits.
  20. GRB050509B: Optical/Infared observations
  21. GRB 050509b: Swift/UVOT follow-up measurements
  22. GRB 050509b Milagro GeV/TeV Observations
  23. GRB050509B: Optical observations at the Very Large Telescope
  24. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  25. GRB 050509a: Swift-BAT refined analysis
  26. GRB 050509B: WSRT Radio Observations
  27. GRB 050505: SARA Observations
  28. Swift UVOT Follow-up Observations of GRB 050509B
  29. GRB 050509B, Optical Observations
  30. GRB 050509B: Swift/XRT refined analysis
  31. GRB050509a: Swift UVOT observations
  32. GRB 050509b: Optical observations
  33. GRB 050509b: Possible Optical Counterpart
  34. GRB 050509A: Optical observations
  35. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  36. GRB 050509b: optical observations
  37. GRB 050509b: Swift XRT Position
  38. GRB 050509B: ROTSE-III Optical Limits
  39. Swift Detection of GRB050509b: A short duration burst
  40. GRB 050509a: Swift XRT Position
  41. Swift Detection of the Burst GRB050509
  42. Swift-BAT detection of GRB 050507
  43. GRB 050505: early time observations
  44. GRB 050505 - Faulkes Telescope North observations
  45. GRB 050502a: Swift XRT Upper Limit
  46. GRB 050505, simultaneous optical observation
  47. GRB 050505: Further Swift UVOT observations.
  48. GRB050416A : 1 GHz limit from GMRT
  49. GRB 050505 UVOT
  50. GRB 050505: Swift XRT Position
  51. GRB050505 Swift-BAT refined analysis
  52. GRB 050416b:Swift XRT afterglow upper limits
  53. GRB 050416b:Swift XRT afterglow upper limits
  54. Swift-BAT detection of GRB050505
  55. GRB 050504: Swift XRT position
  56. Swift UVOT observation of GRB 050504
  57. GRB 050502b, V band Observations
  58. GRB050502B Swift-BAT refined analysis
  59. GRB050502B: I band source in XRT error circle
  60. Swift UVOT refined analysis
  61. Retraction of Swift-BAT trigger 116145
  62. GRB 050502b : optical observation at Lulin observatory
  63. GRB 050502b: Swift XRT Position
  64. GRB050502B: Optical Limits from ANU 1m
  65. Swift Detection of the Bright Burst GRB050502b
  66. GRB050502: ANU 1m optical Observations
  67. Swift-BAT Trigger 115881 is not a real GRB
  68. Swift/BAT possible detection of a weak burst GRB050430
  69. GRB 050401: Rc observation
  70. GRB050416a: Radio Detection
  71. GRB 050422: Swift-UVOT observation
  72. GRB 050422: Swift-BAT refined analysis
  73. GRB 050422: Swift XRT Position
  74. Swift Detection of GRB 050422
  75. GRB 050421: SLOTIS observations
  76. GRB050421: Radio Observations
  77. GRB050421: Radio Observations
  78. GRB 050421: Swift-UVOT observation
  79. GRB 050421: Swift-BAT refined analysis
  80. GRB 050421: ROTSE-III Optical Limits
  81. GRB 050421: early Swift XRT analysis results
  82. GRB 050421: BOOTES-2 simultaneous optical observations
  83. GRB 050421: Optical observations at the INT
  84. Swift Detection of GRB050421
  85. GRB 050416b: Tentative Swift XRT Position
  86. GRB050326: analysis of the XMM-Newton observation
  87. GRB 050418: Swift-BAT refined analysis
  88. Swift-BAT detection of the bright and long GRB 050418
  89. GRB 050416B: optical observations
  90. GRB 050416b: Swift-BAT refined analysis
  91. GRB 050416: Swift/UVOT refined analysis
  92. Swift-BAT detection of GRB 050416b
  93. GRB050412: Radio Observations
  94. GRB 050416: Swift/UVOT detection of afterglow emission
  95. GRB050416: Refined Swift-XRT analysis
  96. GRB050416: Maidanak optical observations
  97. GRB 050416: Swift-BAT refined analysis
  98. GRB 050416,optical observation
  99. GRB 050416: KAIT observations
  100. GRB 050416: Swift XRT Position

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