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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"

21455 results found.

  1. GRB 061004: Las Campanas Optical/NIR Observations
  2. GRB061004: Swift/UVOT optical observations
  3. GRB 061004: Swift-XRT Team Refined Analysis
  4. GRB 061004, Swift BAT refined analysis
  5. GRB 061004: Nearby 2MASS Galaxy
  6. GRB 061004: Swift detection of a burst
  7. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  8. GRB 060928: Swift observations
  9. IPN triangulation of GRB060928 (long, exceptionally bright)
  10. GRB061002: Swift UVOT followup observations
  11. GRB 061002: Swift-XRT Team Refined Analysis
  12. GRB 061002, Swift-BAT refined analysis
  13. GRB061002: MASTER-VWF-Kislovodsk observations
  14. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  15. GRB 061002: Swift detection of a burst
  16. GRB 060929: Further XRT Refined Analysis
  17. GRB 060929: Swift/UVOT Optical Observations
  18. GRB060929: Swift-XRT refined analysis.
  19. GRB 060929, Swift-BAT further refined analysis - late-time flare
  20. GRB 060929: TNG K-band observations
  21. GRB 060929, Swift-BAT refined analysis
  22. GRB060929: Optical limit
  23. GRB 060929: BART observation
  24. GRB 060929: MASTER-VWF-Kislovodsk observations
  25. GRB 060929: BOOTES-IR & OSN observations
  26. Liverpool Telescope observations of GRB 060929
  27. GRB 060929: Swift detection of a burst
  28. GRB 060729: An update on the late-time Swift observations
  29. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  30. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  31. GRB 060927: Swift/UVOT Optical Observations
  32. GRB 060927: Swift XRT Team refined analysis
  33. GRB 060927, Swift-BAT refined analysis
  34. GRB 060927 : Kiso optical observation
  35. GRB060927: Faulkes Telescope South observation
  36. GRB060927 - SDSS Pre-Burst Observations
  37. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  38. Swift XRT boresight
  39. GRB 060927: Swift detection of a burst
  40. GRB060926: VLT redshift
  41. GRB 060926: Swift-UVOT Detections
  42. GRB 060926: Swift XRT refined analysis
  43. GRB 060926, Swift-BAT refined analysis
  44. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  45. GRB 060926: BOOTES-IR observations
  46. GRB060926 OPTIMA-Burst optical observation
  47. GRB 060926: Swift detection of a burst
  48. GRB 060923C, Swift-BAT refined analysis
  49. GRB 060923C: VLA Observation
  50. GRB 060923C: Gemini Observations and Afterglow Candidate
  51. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  52. GRB 060923C: VLT J-band observations
  53. GRB060923B: Swift/UVOT upper limits
  54. GRB 060923B: Swift XRT Refined Analysis
  55. GRB 060923C: Swift XRT refined analysis
  56. GRB 060923C, Swift-BAT partial refined analysis
  57. GRB 060923A: Swift XRT refined analysis
  58. GRB 060923C: Keck Observations
  59. GRB 060923A: Keck and Gemini Observations
  60. GRB 060923B, Swift-BAT refined analysis
  61. GRB060923C : Faulkes Telescope South optical limits
  62. GRB060923C: Faulkes Telescope North optical observations
  63. GRB 060923C: Swift detection of a burst
  64. GRB 060923B: Swift detection of a burst
  65. GRB 060923, Swift-BAT refined analysis
  66. GRB 060923: Early Super-LOTIS Observations
  67. GRB 060923: UKIRT nIR observations - candidate afterglow
  68. GRB060923: Faulkes Telescope North optical observations
  69. GRB 060923: KAIT observations
  70. GRB 060923: Swift detection of a burst
  71. Swift detection of IGR J17497-2821 (trigger 230504)
  72. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  73. GRB060919: Swift/UVOT optical observations
  74. GRB 060919 : Faulkes South Telescope Observations
  75. GRB 060919, Swift-BAT refined analysis
  76. GRB060919: XRT refined analysis
  77. GRB 060919: TAROT optical observations
  78. GRB 060919: Swift detection of a burst
  79. GRB 060912A: VLA Observation
  80. GRB060825: MAGIC telescope GeV observation
  81. Konus-Wind observation of GRB 060912
  82. GRB060912: Swift/UVOT Observations
  83. GRB060912: OPTIMA-Burst optical observations
  84. GRB 060912: Swift XRT Team Refined Analysis
  85. GRB 060912, Swift-BAT refined analysis
  86. GRB 060912: Swift detection of a burst with an optical afterglow
  87. VLA observations of GRB 060908
  88. GRB 060908, Swift/XRT refined analysis
  89. GRB 060908: Swift/UVOT Observations
  90. GRB 060908, Swift-BAT refined analysis
  91. GRB 060908 - SDSS Pre-burst Observations
  92. GRB 060908: Swift detection of a burst with a bright optical counterpart
  93. GRB 060904A: Suzaku/WAM observation of the prompt emission
  94. GRB060904b optical detections (delayed report due to internet outage)
  95. GRB 060906: Early RAPTOR optical limits
  96. GRB 060906, Swift-BAT refined spectral analysis
  97. GRB 060906: Swift/XRT Refined Analysis
  98. GRB 060906: Swift-UVOT observations
  99. VLT redshift of GRB 060906
  100. GRB 060906, Swift-BAT refined analysis

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