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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"

18634 results found.

  1. GRB 060926: Swift-UVOT Detections
  2. GRB 060926: Swift XRT refined analysis
  3. GRB 060926, Swift-BAT refined analysis
  4. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  5. GRB 060926: BOOTES-IR observations
  6. GRB060926 OPTIMA-Burst optical observation
  7. GRB 060926: Swift detection of a burst
  8. GRB 060923C, Swift-BAT refined analysis
  9. GRB 060923C: VLA Observation
  10. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  11. GRB060923B: Swift/UVOT upper limits
  12. GRB 060923B: Swift XRT Refined Analysis
  13. GRB 060923C: Swift XRT refined analysis
  14. GRB 060923C, Swift-BAT partial refined analysis
  15. GRB 060923A: Swift XRT refined analysis
  16. GRB 060923A: Keck and Gemini Observations
  17. GRB 060923B, Swift-BAT refined analysis
  18. GRB060923C : Faulkes Telescope South optical limits
  19. GRB060923C: Faulkes Telescope North optical observations
  20. GRB 060923C: Swift detection of a burst
  21. GRB 060923B: Swift detection of a burst
  22. GRB 060923, Swift-BAT refined analysis
  23. GRB 060923: Early Super-LOTIS Observations
  24. GRB060923: Faulkes Telescope North optical observations
  25. GRB 060923: KAIT observations
  26. GRB 060923: Swift detection of a burst
  27. Swift detection of IGR J17497-2821 (trigger 230504)
  28. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  29. GRB060919: Swift/UVOT optical observations
  30. GRB 060919, Swift-BAT refined analysis
  31. GRB060919: XRT refined analysis
  32. GRB 060919: TAROT optical observations
  33. GRB 060919: Swift detection of a burst
  34. GRB 060912A: VLA Observation
  35. GRB060825: MAGIC telescope GeV observation
  36. Konus-Wind observation of GRB 060912
  37. GRB060912: Swift/UVOT Observations
  38. GRB060912: OPTIMA-Burst optical observations
  39. GRB 060912: Swift XRT Team Refined Analysis
  40. GRB 060912, Swift-BAT refined analysis
  41. GRB 060912: Swift detection of a burst with an optical afterglow
  42. VLA observations of GRB 060908
  43. GRB 060908, Swift/XRT refined analysis
  44. GRB 060908: Swift/UVOT Observations
  45. GRB 060908, Swift-BAT refined analysis
  46. GRB 060908 - SDSS Pre-burst Observations
  47. GRB 060908: Swift detection of a burst with a bright optical counterpart
  48. GRB 060904A: Suzaku/WAM observation of the prompt emission
  49. GRB060904b optical detections (delayed report due to internet outage)
  50. GRB 060906: Early RAPTOR optical limits
  51. GRB 060906, Swift-BAT refined spectral analysis
  52. GRB 060906: Swift/XRT Refined Analysis
  53. GRB 060906: Swift-UVOT observations
  54. VLT redshift of GRB 060906
  55. GRB 060906, Swift-BAT refined analysis
  56. GRB 060906: KAIT observations
  57. GRB 060906 (?): P60 Optical Afterglow Candidate
  58. GRB 060906: Swift detection of a probable burst
  59. GRB 060904A Milagro GeV/TeV Observations
  60. GRB060904A: Swift/UVOT optical observations
  61. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  62. GRB 060904B: Swift-BAT refined analysis
  63. GRB060904b: Optical observations with Swift/UVOT
  64. Konus-Wind observation of GRB 060904A
  65. GRB 060904B: Swift-XRT refined analysis
  66. GRB 060904A: Refined analysis of the Swift-BAT burst
  67. GRB 060904A: Swift-XRT refined analysis
  68. GRB 060904A: Suzaku-XIS and -HXD observation plan
  69. GRB 060904B: Optical observations at Crni Vrh
  70. GRB060904B: Watcher observations
  71. GRB 060904B BOOTES-IR and 1.5m OSN observations
  72. GRB 060904B: TAROT optical counterpart observations
  73. GRB060904B - SDSS Pre-Burst Observations
  74. GRB 060904: TAROT optical observations
  75. GRB 060904B: Swift detection of a burst with optical counterpart
  76. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  77. GRB060904 - SDSS Pre-Burst Observations
  78. GRB 060904: Swift detection of a bright burst
  79. 060901: Swift UVOT followup observations
  80. GRB 060901: Swift/XRT Refined Analysis
  81. GRB 060901: Swift/XRT Position
  82. GRB 060604: VLA Observation
  83. GRB 060814: Suzaku/WAM observation of the prompt emission
  84. GRB 060605: VLA Observation
  85. GRB 060707: VLA observation
  86. GRB 060825: VLA observations
  87. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  88. Swift-BAT trigger 226614 is not a GRB
  89. GRB060826 - SDSS Pre-Burst Observations
  90. GRB 060826(?): Swift detection of a possible burst
  91. GRB 060825: XRT Team Refined Analysis
  92. GRB 060825: Swift-BAT Refined Analysis
  93. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  94. GRB060825: Liverpool Telescope optical observations
  95. GRB 060825: TAROT optical observations
  96. GRB060825: BOOTES-IR optical observations
  97. GRB 060825: Swift detection of a burst
  98. GRB060729: analysis of XMM-Newton observation
  99. GRB 060814: pseudo-z from spectral parameters of the prompt
  100. Radio observations of GRB 060719

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