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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"

35427 results found.

  1. GRB060930: Faulkes Telescope South observation
  2. GRB 060930: Xinglong TNT optical observations
  3. GRB 060929: Further XRT Refined Analysis
  4. GRB 060929: Swift/UVOT Optical Observations
  5. GRB 060930: ROTSE-III Optical Limits
  6. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  7. GRB 060927 : GAO 150cm telescope optical observation
  8. GRB060929: Swift-XRT refined analysis.
  9. GRB 060929, Swift-BAT further refined analysis - late-time flare
  10. GRB 060929: TNG K-band observations
  11. GRB 060929, Swift-BAT refined analysis
  12. GRB 060929: BART observation
  13. GRB 060929: MASTER-VWF-Kislovodsk observations
  14. GRB 060929: BOOTES-IR & OSN observations
  15. Liverpool Telescope observations of GRB 060929
  16. GRB 060929: Swift detection of a burst
  17. GRB060908: optical observations
  18. GRB 060729: An update on the late-time Swift observations
  19. GRB 060927: Spectroscopic redshift z=5.6
  20. IBAS Alert n.3501: not a GRB
  21. IBAS Alert n.3500: not a GRB
  22. GRB060923C: optical limit
  23. GRB060927: optical observations
  24. test of new software, grb
  25. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  26. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  27. GRB 060927: Swift/UVOT Optical Observations
  28. GRB 060927: Early color
  29. GRB 060927: Swift XRT Team refined analysis
  30. GRB 060927 optical limit
  31. GRB 060927, Swift-BAT refined analysis
  32. GRB 060927: Xinglong TNT optical observations
  33. GRB060926: improved redshift
  34. GRB 060927, optical observation
  35. GRB 060927: Possible host galaxy (star?) in the SDSS
  36. GRB 060927 : Kiso optical observation
  37. GRB060927: Faulkes Telescope South observation
  38. GRB 060926: MASTER: first minutes decay
  39. GRB060927 - SDSS Pre-Burst Observations
  40. GRB 060927: optical afterglow confirmation
  41. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  42. GRB 060927: Swift detection of a burst
  43. GRB 060926: Swift-UVOT Detections
  44. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  45. GRB 060926: OPTIMA-Burst -- further observations
  46. GRB 060926: Swift XRT refined analysis
  47. GRB 060926, Swift-BAT refined analysis
  48. GRB 060923A: Radio Observations
  49. GRB 060926: MASTER OT alert observation
  50. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  51. GRB 060912A: Redshift of probable host galaxy
  52. GRB 060926: BOOTES-IR observations
  53. GRB 060926: Watcher observations
  54. GRB060926 OPTIMA-Burst optical observation
  55. GRB 060926: MASTER optical observation
  56. GRB 060926: Swift detection of a burst
  57. GRB 060923C, Swift-BAT refined analysis
  58. GRB 060923C: VLA Observation
  59. GRB 060923C: NIR afterglow confirmed
  60. GRB060923C: AROMA optical obsevation
  61. GRB 060923C: Gemini Observations and Afterglow Candidate
  62. GRB 060923C, optical observation
  63. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  64. GRB 060923C: VLT J-band observations
  65. GRB060923B: Swift/UVOT upper limits
  66. GRB 060923B: Swift XRT Refined Analysis
  67. GRB 060923C: Swift XRT refined analysis
  68. GRB 060923C, Swift-BAT partial refined analysis
  69. GRB 060923A: Swift XRT refined analysis
  70. GRB 060923C: Keck Observations
  71. GRB 060923A: Keck and Gemini Observations
  72. GRB 060923C: Xinglong TNT optical observations
  73. GRB 060923B, Swift-BAT refined analysis
  74. GRB060923C : Faulkes Telescope South optical limits
  75. GRB060923C: Faulkes Telescope North optical observations
  76. GRB 060923C: optical observation
  77. GRB 060923C: Swift detection of a burst
  78. GRB 060923B: Swift detection of a burst
  79. GRB 060923, Swift-BAT refined analysis
  80. GRB 060923: Early Super-LOTIS Observations
  81. GRB 060923: UKIRT nIR observations - candidate afterglow
  82. GRB060923 - SDSS Pre-Burst Observations
  83. GRB 060923: KAIT observations
  84. GRB 060923: Swift detection of a burst
  85. Swift detection of IGR J17497-2821 (trigger 230504)
  86. GRB 060919 : Faulkes South Telescope Observations
  87. GRB 060919, Swift-BAT refined analysis
  88. GRB060919: XRT refined analysis
  89. GRB 060919: TAROT optical observations
  90. GRB 060919: Swift detection of a burst
  91. GRB 060912A: VLA Observation
  92. GRB 060912A: Probable Host Galaxy
  93. IBAS Alert n.3470: not a GRB
  94. GRB060825: MAGIC telescope GeV observation
  95. Konus-Wind observation of GRB 060912
  96. IBAS Alert No.3468: not a GRB
  97. GRB 060912: Redshift of nearby 2MASS galaxy
  98. GRB060912: optical observations
  99. GRB 060912B: Watcher observations
  100. GRB060912: OPTIMA-Burst optical observations

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