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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"

19353 results found.

  1. GRB 060929, Swift-BAT further refined analysis - late-time flare
  2. GRB 060929, Swift-BAT refined analysis
  3. GRB 060929: BART observation
  4. GRB 060929: MASTER-VWF-Kislovodsk observations
  5. GRB 060929: BOOTES-IR & OSN observations
  6. Liverpool Telescope observations of GRB 060929
  7. GRB 060929: Swift detection of a burst
  8. GRB 060729: An update on the late-time Swift observations
  9. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  10. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  11. GRB 060927: Swift/UVOT Optical Observations
  12. GRB 060927: Swift XRT Team refined analysis
  13. GRB 060927, Swift-BAT refined analysis
  14. GRB060927: Faulkes Telescope South observation
  15. GRB060927 - SDSS Pre-Burst Observations
  16. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  17. Swift XRT boresight
  18. GRB 060927: Swift detection of a burst
  19. GRB060926: VLT redshift
  20. GRB 060926: Swift-UVOT Detections
  21. GRB 060926: Swift XRT refined analysis
  22. GRB 060926, Swift-BAT refined analysis
  23. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  24. GRB 060926: BOOTES-IR observations
  25. GRB060926 OPTIMA-Burst optical observation
  26. GRB 060926: Swift detection of a burst
  27. GRB 060923C, Swift-BAT refined analysis
  28. GRB 060923C: VLA Observation
  29. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  30. GRB060923B: Swift/UVOT upper limits
  31. GRB 060923B: Swift XRT Refined Analysis
  32. GRB 060923C: Swift XRT refined analysis
  33. GRB 060923C, Swift-BAT partial refined analysis
  34. GRB 060923A: Swift XRT refined analysis
  35. GRB 060923A: Keck and Gemini Observations
  36. GRB 060923B, Swift-BAT refined analysis
  37. GRB060923C : Faulkes Telescope South optical limits
  38. GRB060923C: Faulkes Telescope North optical observations
  39. GRB 060923C: Swift detection of a burst
  40. GRB 060923B: Swift detection of a burst
  41. GRB 060923, Swift-BAT refined analysis
  42. GRB 060923: Early Super-LOTIS Observations
  43. GRB060923: Faulkes Telescope North optical observations
  44. GRB 060923: KAIT observations
  45. GRB 060923: Swift detection of a burst
  46. Swift detection of IGR J17497-2821 (trigger 230504)
  47. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  48. GRB060919: Swift/UVOT optical observations
  49. GRB 060919, Swift-BAT refined analysis
  50. GRB060919: XRT refined analysis
  51. GRB 060919: TAROT optical observations
  52. GRB 060919: Swift detection of a burst
  53. GRB 060912A: VLA Observation
  54. GRB060825: MAGIC telescope GeV observation
  55. Konus-Wind observation of GRB 060912
  56. GRB060912: Swift/UVOT Observations
  57. GRB060912: OPTIMA-Burst optical observations
  58. GRB 060912: Swift XRT Team Refined Analysis
  59. GRB 060912, Swift-BAT refined analysis
  60. GRB 060912: Swift detection of a burst with an optical afterglow
  61. VLA observations of GRB 060908
  62. GRB 060908, Swift/XRT refined analysis
  63. GRB 060908: Swift/UVOT Observations
  64. GRB 060908, Swift-BAT refined analysis
  65. GRB 060908 - SDSS Pre-burst Observations
  66. GRB 060908: Swift detection of a burst with a bright optical counterpart
  67. GRB 060904A: Suzaku/WAM observation of the prompt emission
  68. GRB060904b optical detections (delayed report due to internet outage)
  69. GRB 060906: Early RAPTOR optical limits
  70. GRB 060906, Swift-BAT refined spectral analysis
  71. GRB 060906: Swift/XRT Refined Analysis
  72. GRB 060906: Swift-UVOT observations
  73. VLT redshift of GRB 060906
  74. GRB 060906, Swift-BAT refined analysis
  75. GRB 060906: KAIT observations
  76. GRB 060906 (?): P60 Optical Afterglow Candidate
  77. GRB 060906: Swift detection of a probable burst
  78. GRB 060904A Milagro GeV/TeV Observations
  79. GRB060904A: Swift/UVOT optical observations
  80. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  81. GRB 060904B: Swift-BAT refined analysis
  82. GRB060904b: Optical observations with Swift/UVOT
  83. Konus-Wind observation of GRB 060904A
  84. GRB 060904B: Swift-XRT refined analysis
  85. GRB 060904A: Refined analysis of the Swift-BAT burst
  86. GRB 060904A: Swift-XRT refined analysis
  87. GRB 060904A: Suzaku-XIS and -HXD observation plan
  88. GRB 060904B: Optical observations at Crni Vrh
  89. GRB060904B: Watcher observations
  90. GRB 060904B BOOTES-IR and 1.5m OSN observations
  91. GRB 060904B: TAROT optical counterpart observations
  92. GRB060904B - SDSS Pre-Burst Observations
  93. GRB 060904: TAROT optical observations
  94. GRB 060904B: Swift detection of a burst with optical counterpart
  95. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  96. GRB060904 - SDSS Pre-Burst Observations
  97. GRB 060904: Swift detection of a bright burst
  98. 060901: Swift UVOT followup observations
  99. GRB 060901: Swift/XRT Refined Analysis
  100. GRB 060901: Swift/XRT Position

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