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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"

21467 results found.

  1. GRB 061006: Swift/UVOT optical observations
  2. Konus-Wind observation of the short hard GRB 061006
  3. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  4. GRB 061007: Swift detection of a burst with an optical counterpart
  5. GRB 061007: ROTSE-III Detection of Optical Counterpart
  6. GRB 061006: VLT observation
  7. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  8. GRB 061006: Swift-XRT Team Refined Analysis
  9. GRB061006 (Swift 232585) might be a short-hard GRB
  10. GRB061006: Faulkes Telescope South Observations
  11. GRB 061006: Swift detection of a burst
  12. GRB 061004: Optical afterglow candidate and redshift
  13. GRB 061004: Las Campanas Optical/NIR Observations
  14. GRB061004: Swift/UVOT optical observations
  15. GRB 061004: Swift-XRT Team Refined Analysis
  16. GRB 061004, Swift BAT refined analysis
  17. GRB 061004: Nearby 2MASS Galaxy
  18. GRB 061004: Swift detection of a burst
  19. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  20. GRB 060928: Swift observations
  21. IPN triangulation of GRB060928 (long, exceptionally bright)
  22. GRB061002: Swift UVOT followup observations
  23. GRB 061002: Swift-XRT Team Refined Analysis
  24. GRB 061002, Swift-BAT refined analysis
  25. GRB061002: MASTER-VWF-Kislovodsk observations
  26. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  27. GRB 061002: Swift detection of a burst
  28. GRB 060929: Further XRT Refined Analysis
  29. GRB 060929: Swift/UVOT Optical Observations
  30. GRB060929: Swift-XRT refined analysis.
  31. GRB 060929, Swift-BAT further refined analysis - late-time flare
  32. GRB 060929: TNG K-band observations
  33. GRB 060929, Swift-BAT refined analysis
  34. GRB060929: Optical limit
  35. GRB 060929: BART observation
  36. GRB 060929: MASTER-VWF-Kislovodsk observations
  37. GRB 060929: BOOTES-IR & OSN observations
  38. Liverpool Telescope observations of GRB 060929
  39. GRB 060929: Swift detection of a burst
  40. GRB 060729: An update on the late-time Swift observations
  41. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  42. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  43. GRB 060927: Swift/UVOT Optical Observations
  44. GRB 060927: Swift XRT Team refined analysis
  45. GRB 060927, Swift-BAT refined analysis
  46. GRB 060927 : Kiso optical observation
  47. GRB060927: Faulkes Telescope South observation
  48. GRB060927 - SDSS Pre-Burst Observations
  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 060926: Swift XRT refined analysis
  55. GRB 060926, Swift-BAT refined analysis
  56. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  57. GRB 060926: BOOTES-IR observations
  58. GRB060926 OPTIMA-Burst optical observation
  59. GRB 060926: Swift detection of a burst
  60. GRB 060923C, Swift-BAT refined analysis
  61. GRB 060923C: VLA Observation
  62. GRB 060923C: Gemini Observations and Afterglow Candidate
  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 060923B, Swift-BAT refined analysis
  73. GRB060923C : Faulkes Telescope South optical limits
  74. GRB060923C: Faulkes Telescope North optical observations
  75. GRB 060923C: Swift detection of a burst
  76. GRB 060923B: Swift detection of a burst
  77. GRB 060923, Swift-BAT refined analysis
  78. GRB 060923: Early Super-LOTIS Observations
  79. GRB 060923: UKIRT nIR observations - candidate afterglow
  80. GRB060923: Faulkes Telescope North optical observations
  81. GRB 060923: KAIT observations
  82. GRB 060923: Swift detection of a burst
  83. Swift detection of IGR J17497-2821 (trigger 230504)
  84. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  85. GRB060919: Swift/UVOT optical observations
  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. GRB060825: MAGIC telescope GeV observation
  93. Konus-Wind observation of GRB 060912
  94. GRB060912: Swift/UVOT Observations
  95. GRB060912: OPTIMA-Burst optical observations
  96. GRB 060912: Swift XRT Team Refined Analysis
  97. GRB 060912, Swift-BAT refined analysis
  98. GRB 060912: Swift detection of a burst with an optical afterglow
  99. VLA observations of GRB 060908
  100. GRB 060908, Swift/XRT refined analysis

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