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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"

21456 results found.

  1. GRB 050802: Swift-BAT refined analysis
  2. GRB050801: Optical photometry and decay index
  3. GRB 050802: XRT position
  4. GRB 050802: Swift Gamma-ray Burst
  5. GRB050801: Swift/UVOT Optical and UV detections
  6. GCN 050801: early Swift XRT analysis results
  7. GRB 050801: Swift-BAT refined analysis
  8. GRB 050801, afterglow observations
  9. GRB 050730, corrected photometry and break?
  10. GRB 050801: ROTSE-III Early Afterglow Break
  11. GRB050801: Swift-BAT detection of a burst
  12. GRB050801: GCN XRT position is incorrect
  13. GRB 050801: ROTSE-III Detection of Possible Counterpart
  14. GRB 050730: XRT refined analysis
  15. GRB 050730: early TAROT optical observations
  16. GRB 050726: PROMPT Rc Observations
  17. Swift/UVOT photometry of GRB050730
  18. GRB050730: Refined BAT analysis of the Swift-BAT burst
  19. GRB 050730: Swift XRT afterglow observations
  20. GRB 050730 XMM-Newton observation
  21. GRB050730, afterglow observations
  22. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  23. GRB050730: Liverpool Telescope optical observations
  24. GRB 050730, optical candidate
  25. GRB050730: Swift-BAT detection of a weak burst
  26. GRB 050713A: Swift XRT extended light curve
  27. GRB050713b: Maidanak optical observations
  28. GRB050726: Swift UVOT observations
  29. GRB 050724: Chandra Observations of the X-ray Afterglow
  30. GRB050713: analysis of the XMM-Newton observation
  31. Swift-BAT trigger 147918 is not a real GRB
  32. GRB 050727: RTT150 optical observations
  33. GRB050727: KAIT optical limit
  34. GRB 050726: PROMPT Rc Observations
  35. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  36. GRB050724: Further Radio Observations
  37. GRB 050726: early Swift XRT analysis results
  38. GRB050726: Swift-BAT detection of a weak burst
  39. GRB 050724: J-band observations
  40. GRB 050724: GMOS Imaging and Spectroscopy
  41. GRB 050724: SWIFT XRT refined position
  42. GRB050724: Radio Observation
  43. GRB 050724: spectroscopy of object in the XRT error circle
  44. GRB 050724: optical and near-IR observations
  45. GRB 050724: Optical imaging/astrometry
  46. GRB 050724: Swift/UVOT Upper Limit
  47. GRB 050724: early Swift XRT analysis results
  48. GRB050724: Refined analysis of the Swift-BAT possible short burst
  49. GRB 050724: possible host galaxy in DSS
  50. GRB050724: a short-burst detected by Swift
  51. Swift-BAT trigger 147325 is not due to a real GRB
  52. GRB050723: XRT distributed coordinates are not related to the burst
  53. GRB 050721A: Swift-BAT refined analysis
  54. GRB 050721A: Early Swift XRT analysis results
  55. GRB 050721: optical afterglow confirmed
  56. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  57. GRB 050721a: Optical Observations
  58. GRB050721A: Swift-BAT detection of a weak burst
  59. GRB 050717: PROMPT RcIc Observations
  60. GRB050714b: Radio Observation
  61. GRB 050714a: Refined XRT analysis and afterglow confirmation
  62. Swift-BAT trigger 146731 is not a real GRB
  63. Swift-BAT detection of a possible GRB
  64. GRB 050714B: VLT R-band observations
  65. GRB 050717: Additional LCO observations
  66. GRB050717
  67. Konus-Wind observation of GRB 050717
  68. GRB 050717: LCO near-IR observations
  69. Swift/UVOT Observations of GRB 050717
  70. GRB 050717: Swift-BAT refined analysis
  71. GRB 050717: Refined XRT analysis.
  72. GRB050712: optical limits
  73. GRB050717: Swift XRT position
  74. Swift detection of GRB 050717
  75. GRB 050716 - UKIRT identification of candidate afterglow
  76. Swift UVOT Observations of GRB 050716
  77. GRB 050716: Refined XRT analysis.
  78. GRB050716: Refined analysis of the Swift-BAT burst
  79. GRB050716, optical observation
  80. GRB050716: Faulkes North Telescope observation
  81. GRB050716: Correction to sign in XRT coordinate
  82. Swift/BAT detection of GRB 050716
  83. GRB050715: Refined analysis of the Swift-BAT burst
  84. GRB 050715: Swift-BAT detection
  85. Swift UVOT Observations of GRB 050714B
  86. Konus-Wind observation of GRB 050713A
  87. GRB 050714B: refined XRT analysis
  88. GRB 050714B: candidate afterglow does not fade
  89. GRB050714B: Refined analysis of the Swift-BAT burst
  90. GRB 050714B: optical afterglow
  91. Swift detection of a long transient (GRB 050714B?)
  92. GRB 050714: Swift XRT afterglow position
  93. GRB 050713A: XRT refined analysis
  94. GRB 050713A: RAPTOR detection of early optical emission
  95. GRB050713B :Swift/UVOT observations
  96. GRB050713b: XRT refined analysis
  97. GRB050712: TNG R-band observations
  98. GRB 050713B: Swift-BAT Refined Analysis
  99. Swift-BAT Trigger 145729 is not a GRB
  100. GRB 050713A: Swift/UVOT observation

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