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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"

42185 results found.

  1. GRB050724: Further Radio Observations
  2. GRB 050726: early Swift XRT analysis results
  3. GRB050726: Swift-BAT detection of a weak burst
  4. GRB 050724: Optical Variability in Nearby Galaxy
  5. GRB 050724: J-band observations
  6. GRB 050724: GMOS Imaging and Spectroscopy
  7. GRB 050724: SWIFT XRT refined position
  8. RXTE ASM Detection of GRB050724
  9. GRB050724: Radio Observation
  10. GRB 050724: spectroscopy of object in the XRT error circle
  11. GRB 050724: Optical limit
  12. GRB 050724: optical and near-IR observations
  13. GRB 050724: Optical imaging/astrometry
  14. GRB 050724: RTT150 optical observations
  15. GRB 050724: Swift/UVOT Upper Limit
  16. GRB 050724: early Swift XRT analysis results
  17. GRB050724: Refined analysis of the Swift-BAT possible short burst
  18. GRB 050724: possible host galaxy in DSS
  19. GRB050724: a short-burst detected by Swift
  20. GRB050723: XRT distributed coordinates are not related to the burst
  21. GRB 050721: early afterglow light curve
  22. GRB 050721A: Swift-BAT refined analysis
  23. GRB 050721A: Early Swift XRT analysis results
  24. GRB050721A: optical decay
  25. GRB 050721: optical afterglow confirmed
  26. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  27. GRB 050721a: Optical Observations
  28. GRB050721A: Swift-BAT detection of a weak burst
  29. GRB 050709: Refined Spectral and Temporal Properties
  30. GRB050714b: Radio Observation
  31. GRB050712: Radio Observations
  32. GRB 050714a: Refined XRT analysis and afterglow confirmation
  33. GRB050713a: Radio Observation
  34. GRB 050712, Tautenburg optical afterglow observations
  35. Swift-BAT detection of a possible GRB
  36. GRB 050714B: VLT R-band observations
  37. GRB 050717: Additional LCO observations
  38. GRB050717
  39. GRB 050716; J-band observations
  40. Konus-Wind observation of GRB 050717
  41. GRB 050717: LCO near-IR observations
  42. GRB 050717: Swift-BAT refined analysis
  43. GRB 050717: Refined XRT analysis.
  44. GRB050712: optical limits
  45. GRB050717: Swift XRT position
  46. Swift detection of GRB 050717
  47. GRB 050716 - UKIRT identification of candidate afterglow
  48. GRB 050716: Refined XRT analysis.
  49. GRB050716: Refined analysis of the Swift-BAT burst
  50. GRB 050716: Lulin B and R band optical observations
  51. GRB050716, optical observation
  52. GRB 050716: Optical Observations
  53. GRB050716: Faulkes North Telescope observation
  54. GRB050716: Correction to sign in XRT coordinate
  55. Swift/BAT detection of GRB 050716
  56. GRB050715: Refined analysis of the Swift-BAT burst
  57. GRB 050715: Swift-BAT detection
  58. Swift UVOT Observations of GRB 050714B
  59. Konus-Wind observation of GRB 050713A
  60. GRB 050714B: refined XRT analysis
  61. GRB 050713b: RTT150 optical observations
  62. GRB 050714B: candidate afterglow does not fade
  63. GRB050714B: Refined analysis of the Swift-BAT burst
  64. GRB 050714B: optical afterglow
  65. Swift detection of a long transient (GRB 050714B?)
  66. GRB 050709: optical afterglow candidate
  67. GRB 050714: Swift XRT afterglow position
  68. GRB 050714, optical observations
  69. GRB 050714A: ROTSE-III Optical Limits
  70. GRB 050714 - A long GRB detected with INTEGRAL
  71. GRB 050713A: XRT refined analysis
  72. GRB 050709: Spectroscopy
  73. GRB 050713A: RAPTOR detection of early optical emission
  74. GRB050713b: XRT refined analysis
  75. GRB050712: TNG R-band observations
  76. GRB 050713B: Swift-BAT Refined Analysis
  77. GRB 050713A : Swift-BAT Refined Analysis
  78. GRB050712: Swift UVOT Observation of Afterglow Emission
  79. GRB 050713A : Lulin R-band observation
  80. GRB 050713A XMM-Newton observation
  81. GRB 050713b : Lulin R-band observations
  82. GRB050713B: Faulkes North Telescope observation
  83. RBO RI observations of GRB 050713A
  84. GRB 050713B
  85. GRB050709 : Chandra source optical counterpart
  86. GRB050713: Liverpool Telescope prompt observations
  87. GRB 050712, optical observations
  88. GRB 050713 : Planned XMM-Newton observation
  89. GRB050709: Candidate X-ray Afterglow from Chandra
  90. GRB 050713, R-band observations at NOT
  91. GRB 050713: ARC NIR Detections and Identification of Fading
  92. GRB050713: possible I-band afterglow
  93. GRB 050713: Swift detection of Bright Burst
  94. GRB 050713A: ROTSE-III Optical Limits
  95. GRB050712: XRT refined analysis
  96. GRB050709: Radio Observations
  97. GRB 050709: Swift UVOT and XRT observations
  98. GRB 050712: Swift-BAT Refined Analysis
  99. GRB050712: UVOT candidate optical counterpart
  100. GRB 050712: Swift XRT afterglow position

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