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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"

19533 results found.

  1. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  2. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  3. XRF 050522: Swift XRT refined analysis
  4. Swift/UVOT observation of XRF 050522
  5. GRB 050509A: Further I-band imaging
  6. RBO Observations of GRB050522
  7. XRF 050522: Swift XRT observation
  8. GRB 050520: VLT/ULTRACAM observations
  9. Swift UVOT Observations of GRB 050520
  10. GRB 050520: Swift XRT refined analysis
  11. XRF050509C: Chandra Afterglow Detection
  12. XRF 050509c: Swift XRT Upper Limit
  13. RBO Observations of GRB050520
  14. GRB 050520: TAROT optical limit
  15. GRB 050520: Swift XRT position
  16. No Swift-BAT Lightcurves in real-time for next 3 weeks
  17. Swift-BAT trigger 122203 is not a real GRB
  18. GRB 050504: Swift XRT afterglow candidate has faded
  19. GRB 050509B: Subaru Optical Observations
  20. GRB050502b: Early Observation
  21. Refined Chandra analysis of GRB 050509b
  22. GRB050509b, SDSS pre-burst observations
  23. Chandra observation of GRB 050509b
  24. GRB 050509b: RAPTOR deep, early limits.
  25. GRB050509B: Optical/Infared observations
  26. GRB 050509b: Swift/UVOT follow-up measurements
  27. GRB 050509b Milagro GeV/TeV Observations
  28. GRB050509B: Optical observations at the Very Large Telescope
  29. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  30. GRB 050509a: Swift-BAT refined analysis
  31. GRB 050509B: WSRT Radio Observations
  32. GRB 050505: SARA Observations
  33. Swift UVOT Follow-up Observations of GRB 050509B
  34. GRB 050509B, Optical Observations
  35. GRB 050509B: Swift/XRT refined analysis
  36. GRB050509a: Swift UVOT observations
  37. GRB 050509b: Optical observations
  38. GRB 050509b: Possible Optical Counterpart
  39. GRB 050509A: Optical observations
  40. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  41. GRB 050509b: optical observations
  42. GRB 050509b: Swift XRT Position
  43. GRB 050509B: ROTSE-III Optical Limits
  44. Swift Detection of GRB050509b: A short duration burst
  45. GRB 050509a: Swift XRT Position
  46. Swift Detection of the Burst GRB050509
  47. Swift-BAT detection of GRB 050507
  48. GRB 050505: early time observations
  49. GRB 050505 - Faulkes Telescope North observations
  50. GRB 050502a: Swift XRT Upper Limit
  51. GRB 050505, simultaneous optical observation
  52. GRB 050505: Further Swift UVOT observations.
  53. GRB050416A : 1 GHz limit from GMRT
  54. GRB 050505 UVOT
  55. GRB 050505: Swift XRT Position
  56. GRB050505 Swift-BAT refined analysis
  57. GRB 050416b:Swift XRT afterglow upper limits
  58. GRB 050416b:Swift XRT afterglow upper limits
  59. Swift-BAT detection of GRB050505
  60. GRB 050504: Swift XRT position
  61. Swift UVOT observation of GRB 050504
  62. GRB 050502b, V band Observations
  63. GRB050502B Swift-BAT refined analysis
  64. GRB050502B: I band source in XRT error circle
  65. Swift UVOT refined analysis
  66. Retraction of Swift-BAT trigger 116145
  67. GRB 050502b : optical observation at Lulin observatory
  68. GRB 050502b: Swift XRT Position
  69. GRB050502B: Optical Limits from ANU 1m
  70. Swift Detection of the Bright Burst GRB050502b
  71. GRB050502: ANU 1m optical Observations
  72. Swift-BAT Trigger 115881 is not a real GRB
  73. Swift/BAT possible detection of a weak burst GRB050430
  74. GRB 050401: Rc observation
  75. GRB050416a: Radio Detection
  76. GRB 050422: Swift-UVOT observation
  77. GRB 050422: Swift-BAT refined analysis
  78. GRB 050422: Swift XRT Position
  79. Swift Detection of GRB 050422
  80. GRB 050421: SLOTIS observations
  81. GRB050421: Radio Observations
  82. GRB050421: Radio Observations
  83. GRB 050421: Swift-UVOT observation
  84. GRB 050421: Swift-BAT refined analysis
  85. GRB 050421: ROTSE-III Optical Limits
  86. GRB 050421: early Swift XRT analysis results
  87. GRB 050421: BOOTES-2 simultaneous optical observations
  88. GRB 050421: Optical observations at the INT
  89. Swift Detection of GRB050421
  90. GRB 050416b: Tentative Swift XRT Position
  91. GRB050326: analysis of the XMM-Newton observation
  92. GRB 050418: Swift-BAT refined analysis
  93. Swift-BAT detection of the bright and long GRB 050418
  94. GRB 050416B: optical observations
  95. GRB 050416b: Swift-BAT refined analysis
  96. GRB 050416: Swift/UVOT refined analysis
  97. Swift-BAT detection of GRB 050416b
  98. GRB050412: Radio Observations
  99. GRB 050416: Swift/UVOT detection of afterglow emission
  100. GRB050416: Refined Swift-XRT analysis

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