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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"

41676 results found.

  1. IPN triangulation of GRB060928 (long, exceptionally bright)
  2. GRB061002: Swift UVOT followup observations
  3. GRB 060930: near-IR afterglow candidate
  4. GRB 061002: Swift-XRT Team Refined Analysis
  5. VLA observations of GRB 060926
  6. GRB061002 - SDSS Pre-Burst Observations
  7. GRB 061002, Swift-BAT refined analysis
  8. GRB061002: MASTER-VWF-Kislovodsk observations
  9. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  10. GRB 061002: Swift detection of a burst
  11. GRB 060908: Detection of a possible host
  12. GRB 060923A: Probable host galaxy in the R-band
  13. GRB 060807: Detection of a possible host galaxy
  14. GRB 060923A: VLA K-band Observations
  15. GRB060930: Faulkes Telescope South observation
  16. GRB 060930: Xinglong TNT optical observations
  17. GRB 060929: Further XRT Refined Analysis
  18. GRB 060929: Swift/UVOT Optical Observations
  19. GRB 060930: ROTSE-III Optical Limits
  20. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  21. GRB 060927 : GAO 150cm telescope optical observation
  22. GRB060929: Swift-XRT refined analysis.
  23. GRB 060929, Swift-BAT further refined analysis - late-time flare
  24. GRB 060929, Swift-BAT refined analysis
  25. GRB060929: Optical limit
  26. GRB 060929: MASTER-VWF-Kislovodsk observations
  27. GRB 060929: BOOTES-IR & OSN observations
  28. GRB 060929: Swift detection of a burst
  29. GRB060908: optical observations
  30. GRB 060729: An update on the late-time Swift observations
  31. GRB 060927: Spectroscopic redshift z=5.6
  32. IBAS Alert n.3501: not a GRB
  33. IBAS Alert n.3500: not a GRB
  34. GRB060923C: optical limit
  35. GRB060927: optical observations
  36. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  37. GRB 060927: Early color
  38. GRB 060927: Swift XRT Team refined analysis
  39. GRB 060927 optical limit
  40. GRB 060927, Swift-BAT refined analysis
  41. GRB 060927: Xinglong TNT optical observations
  42. GRB060926: improved redshift
  43. GRB 060927: Possible host galaxy (star?) in the SDSS
  44. GRB 060927 : Kiso optical observation
  45. GRB060927: Faulkes Telescope South observation
  46. GRB 060926: MASTER: first minutes decay
  47. GRB060927 - SDSS Pre-Burst Observations
  48. GRB 060927: optical afterglow confirmation
  49. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  50. Swift XRT boresight
  51. GRB 060927: Swift detection of a burst
  52. GRB060926: VLT redshift
  53. GRB 060926: Swift-UVOT Detections
  54. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  55. GRB 060926: OPTIMA-Burst -- further observations
  56. GRB 060926: Swift XRT refined analysis
  57. GRB 060926, Swift-BAT refined analysis
  58. GRB 060923A: Radio Observations
  59. GRB 060912A: Redshift of probable host galaxy
  60. GRB 060926: Watcher observations
  61. GRB060926 OPTIMA-Burst optical observation
  62. GRB 060926: Swift detection of a burst
  63. GRB 060923C, Swift-BAT refined analysis
  64. GRB 060923C: VLA Observation
  65. GRB 060923C: NIR afterglow confirmed
  66. GRB060923C: AROMA optical obsevation
  67. GRB 060923C: Gemini Observations and Afterglow Candidate
  68. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  69. GRB 060923C: VLT J-band observations
  70. GRB060923B: Swift/UVOT upper limits
  71. GRB 060923B: Swift XRT Refined Analysis
  72. GRB 060923C: Swift XRT refined analysis
  73. GRB 060923A: Swift XRT refined analysis
  74. GRB 060923C: Keck Observations
  75. GRB 060923A: Keck and Gemini Observations
  76. GRB 060923C: Xinglong TNT optical observations
  77. GRB 060923B, Swift-BAT refined analysis
  78. GRB060923C: Faulkes Telescope North optical observations
  79. GRB 060923C: Swift detection of a burst
  80. GRB 060923B: Swift detection of a burst
  81. GRB 060923, Swift-BAT refined analysis
  82. GRB 060923: Early Super-LOTIS Observations
  83. GRB 060923: UKIRT nIR observations - candidate afterglow
  84. GRB060923: Faulkes Telescope North optical observations
  85. GRB060923 - SDSS Pre-Burst Observations
  86. GRB 060923: KAIT observations
  87. GRB 060923: Swift detection of a burst
  88. Swift detection of IGR J17497-2821 (trigger 230504)
  89. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  90. GRB060919: Swift/UVOT optical observations
  91. GRB 060919 : Faulkes South Telescope Observations
  92. GRB 060919, Swift-BAT refined analysis
  93. GRB060919: XRT refined analysis
  94. GRB 060919: TAROT optical observations
  95. GRB 060919: Swift detection of a burst
  96. GRB 060912A: VLA Observation
  97. GRB 060912A: Probable Host Galaxy
  98. IBAS Alert n.3470: not a GRB
  99. GRB060825: MAGIC telescope GeV observation
  100. Konus-Wind observation of GRB 060912

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