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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').

17956 results found.

  1. GRB 060929: Swift/UVOT Optical Observations
  2. GRB060929: Swift-XRT refined analysis.
  3. GRB 060929, Swift-BAT further refined analysis - late-time flare
  4. GRB 060929, Swift-BAT refined analysis
  5. GRB 060929: BART observation
  6. GRB 060929: MASTER-VWF-Kislovodsk observations
  7. GRB 060929: BOOTES-IR & OSN observations
  8. Liverpool Telescope observations of GRB 060929
  9. GRB 060929: Swift detection of a burst
  10. GRB 060729: An update on the late-time Swift observations
  11. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  12. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  13. GRB 060927: Swift/UVOT Optical Observations
  14. GRB 060927: Swift XRT Team refined analysis
  15. GRB 060927, Swift-BAT refined analysis
  16. GRB060927: Faulkes Telescope South observation
  17. GRB060927 - SDSS Pre-Burst Observations
  18. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  19. Swift XRT boresight
  20. GRB 060927: Swift detection of a burst
  21. GRB060926: VLT redshift
  22. GRB 060926: Swift-UVOT Detections
  23. GRB 060926: Swift XRT refined analysis
  24. GRB 060926, Swift-BAT refined analysis
  25. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  26. GRB 060926: BOOTES-IR observations
  27. GRB060926 OPTIMA-Burst optical observation
  28. GRB 060926: Swift detection of a burst
  29. GRB 060923C, Swift-BAT refined analysis
  30. GRB 060923C: VLA Observation
  31. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  32. GRB060923B: Swift/UVOT upper limits
  33. GRB 060923B: Swift XRT Refined Analysis
  34. GRB 060923C: Swift XRT refined analysis
  35. GRB 060923C, Swift-BAT partial refined analysis
  36. GRB 060923A: Swift XRT refined analysis
  37. GRB 060923A: Keck and Gemini Observations
  38. GRB 060923B, Swift-BAT refined analysis
  39. GRB060923C : Faulkes Telescope South optical limits
  40. GRB060923C: Faulkes Telescope North optical observations
  41. GRB 060923C: Swift detection of a burst
  42. GRB 060923B: Swift detection of a burst
  43. GRB 060923, Swift-BAT refined analysis
  44. GRB 060923: Early Super-LOTIS Observations
  45. GRB060923: Faulkes Telescope North optical observations
  46. GRB 060923: KAIT observations
  47. GRB 060923: Swift detection of a burst
  48. Swift detection of IGR J17497-2821 (trigger 230504)
  49. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  50. GRB060919: Swift/UVOT optical observations
  51. GRB 060919, Swift-BAT refined analysis
  52. GRB060919: XRT refined analysis
  53. GRB 060919: TAROT optical observations
  54. GRB 060919: Swift detection of a burst
  55. GRB 060912A: VLA Observation
  56. GRB060825: MAGIC telescope GeV observation
  57. Konus-Wind observation of GRB 060912
  58. GRB060912: Swift/UVOT Observations
  59. GRB060912: OPTIMA-Burst optical observations
  60. GRB 060912: Swift XRT Team Refined Analysis
  61. GRB 060912, Swift-BAT refined analysis
  62. GRB 060912: Swift detection of a burst with an optical afterglow
  63. VLA observations of GRB 060908
  64. GRB 060908, Swift/XRT refined analysis
  65. GRB 060908: Swift/UVOT Observations
  66. GRB 060908, Swift-BAT refined analysis
  67. GRB 060908 - SDSS Pre-burst Observations
  68. GRB 060908: Swift detection of a burst with a bright optical counterpart
  69. GRB 060904A: Suzaku/WAM observation of the prompt emission
  70. GRB060904b optical detections (delayed report due to internet outage)
  71. GRB 060906: Early RAPTOR optical limits
  72. GRB 060906, Swift-BAT refined spectral analysis
  73. GRB 060906: Swift/XRT Refined Analysis
  74. GRB 060906: Swift-UVOT observations
  75. VLT redshift of GRB 060906
  76. GRB 060906, Swift-BAT refined analysis
  77. GRB 060906: KAIT observations
  78. GRB 060906 (?): P60 Optical Afterglow Candidate
  79. GRB 060906: Swift detection of a probable burst
  80. GRB 060904A Milagro GeV/TeV Observations
  81. GRB060904A: Swift/UVOT optical observations
  82. GRB 060904A: pseudo-z from spectral parameters of the prompt emission
  83. GRB 060904B: Swift-BAT refined analysis
  84. GRB060904b: Optical observations with Swift/UVOT
  85. Konus-Wind observation of GRB 060904A
  86. GRB 060904B: Swift-XRT refined analysis
  87. GRB 060904A: Refined analysis of the Swift-BAT burst
  88. GRB 060904A: Swift-XRT refined analysis
  89. GRB 060904A: Suzaku-XIS and -HXD observation plan
  90. GRB 060904B: Optical observations at Crni Vrh
  91. GRB060904B: Watcher observations
  92. GRB 060904B BOOTES-IR and 1.5m OSN observations
  93. GRB 060904B: TAROT optical counterpart observations
  94. GRB060904B - SDSS Pre-Burst Observations
  95. GRB 060904: TAROT optical observations
  96. GRB 060904B: Swift detection of a burst with optical counterpart
  97. GRB 060904B: ROTSE-III Detection of Optical Counterpart
  98. GRB060904 - SDSS Pre-Burst Observations
  99. GRB 060904: Swift detection of a bright burst
  100. 060901: Swift UVOT followup observations

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