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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"

27408 results found.

  1. GRB 050525B: Swift-BAT observations
  2. GRB050525A,optical observation
  3. GRB050525: Super-LOTIS observations
  4. GRB 050525, spectral lag pseudo-redshift
  5. GRB 050525A: BOOTES simultaneous optical observations
  6. GRB 050525A: Swift-BAT refined analysis
  7. Swift/UVOT UV and optical detections of GRB 050525
  8. Konus-Wind observation of GRB 050525
  9. GRB 050525 - Very Bright, Not Short
  10. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  11. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  12. GRB 050509A: Further I-band imaging
  13. GRB050522,optical observation
  14. GRB050520,optical observation
  15. GRB 050520: VLT/ULTRACAM observations
  16. GRB 050520: BART optical limit
  17. No Swift-BAT Lightcurves in real-time for next 3 weeks
  18. Swift-BAT trigger 122203 is not a real GRB
  19. XRF 050509C: REM NIR and Optical refined analysis
  20. XRF 050509c optical afterglow
  21. GRB050502b: Early Observation
  22. GRB050509b, SDSS pre-burst observations
  23. GRB 050509b: RAPTOR deep, early limits.
  24. GRB 050509b: Swift/UVOT follow-up measurements
  25. GRB050509B: Optical observations at the Very Large Telescope
  26. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  27. GRB 050509a: Swift-BAT refined analysis
  28. GRB 050509c: ROTSE-III Optical Limits
  29. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  30. GRB050509c: REM NIR and Optical observations
  31. Swift UVOT Follow-up Observations of GRB 050509B
  32. GRB 050509B: Swift/XRT refined analysis
  33. GRB050509a: Swift UVOT observations
  34. GRB 050509b: Optical observations
  35. GRB 050509A: Optical observations
  36. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  37. GRB 050509b: optical observations
  38. GRB 050509b: Swift XRT Position
  39. GRB 050509B: ROTSE-III Optical Limits
  40. Swift Detection of GRB050509b: A short duration burst
  41. GRB 050509a: Swift XRT Position
  42. Swift Detection of the Burst GRB050509
  43. Swift-BAT detection of GRB 050507
  44. GRB 050505: early time observations
  45. GRB 050505 - Faulkes Telescope North observations
  46. GRB 050505, simultaneous optical observation
  47. GRB050505: Infrared observations
  48. GRB 050505: Further Swift UVOT observations.
  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. Swift UVOT observation of GRB 050504
  56. GRB050504: Faulkes North optical robotic limit
  57. GRB 050502b, V band Observations
  58. GRB (?) 050504: IR Observations, Intriguing Source
  59. Renewal of SGR 1806-20 activity
  60. GRB050502B Swift-BAT refined analysis
  61. Swift UVOT refined analysis
  62. Retraction of Swift-BAT trigger 116145
  63. GRB 050502b: Swift XRT Position
  64. Swift Detection of the Bright Burst GRB050502b
  65. GRB050502: ANU 1m optical Observations
  66. GRB 050502: ROTSE-III Detection of Possible Counterpart
  67. Swift-BAT Trigger 115881 is not a real GRB
  68. Swift/BAT possible detection of a weak burst GRB050430
  69. GRB 050422: Swift-UVOT observation
  70. GRB 050422: Swift-BAT refined analysis
  71. GRB 050422: Swift XRT Position
  72. Swift Detection of GRB 050422
  73. GRB 050421: SLOTIS observations
  74. GRB050421: Radio Observations
  75. GRB050421: Radio Observations
  76. GRB 050421: Swift-UVOT observation
  77. GRB 050421: Swift-BAT refined analysis
  78. GRB 050421: ROTSE-III Optical Limits
  79. GRB050421
  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. GRB 050418: Swift-BAT refined analysis
  86. Swift-BAT detection of the bright and long GRB 050418
  87. GRB 050416B: optical observations
  88. GRB 050416b: Swift-BAT refined analysis
  89. GRB 050416b: LCO observations
  90. GRB 050416b: LCO observations
  91. GRB050416B: IR observations
  92. GRB 050416: Swift/UVOT refined analysis
  93. Swift-BAT detection of GRB 050416b
  94. GRB 050416: Swift/UVOT detection of afterglow emission
  95. GRB050416: Refined Swift-XRT analysis
  96. GRB 050416: Swift-BAT refined analysis
  97. GRB 050416: ART observations
  98. GRB 050416,optical observation
  99. GRB 050416: KAIT observations
  100. GRB 050416: Swift XRT Position

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