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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"

22077 results found.

  1. GRB 050724: Chandra Observations of the X-ray Afterglow
  2. GRB050713: analysis of the XMM-Newton observation
  3. GRB050709: Second Epoch Chandra Observation
  4. GRB050709: Second Epoch Chandra Observation
  5. GRB 050726: early Swift XRT analysis results
  6. GRB050726: Swift-BAT detection of a weak burst
  7. GRB 050724: Optical Variability in Nearby Galaxy
  8. GRB 050724: J-band observations
  9. GRB 050724: GMOS Imaging and Spectroscopy
  10. GRB 050724: SWIFT XRT refined position
  11. RXTE ASM Detection of GRB050724
  12. GRB050724: Radio Observation
  13. GRB 050724: Optical limit
  14. GRB 050724: Swift/UVOT Upper Limit
  15. GRB050724: Refined analysis of the Swift-BAT possible short burst
  16. GRB 050724: possible host galaxy in DSS
  17. GRB050724: a short-burst detected by Swift
  18. GRB 050721A: Swift-BAT refined analysis
  19. GRB050721A: optical decay
  20. GRB 050721: optical afterglow confirmed
  21. GRB050721A: Swift-BAT detection of a weak burst
  22. GRB 050717: PROMPT RcIc Observations
  23. GRB050714b: Radio Observation
  24. GRB050712: Radio Observations
  25. GRB050713a: Radio Observation
  26. Swift-BAT trigger 146731 is not a real GRB
  27. GRB 050712, Tautenburg optical afterglow observations
  28. Swift-BAT detection of a possible GRB
  29. GRB 050714B: VLT R-band observations
  30. GRB 050717: Additional LCO observations
  31. GRB 050716; J-band observations
  32. GRB 050717: LCO near-IR observations
  33. Swift/UVOT Observations of GRB 050717
  34. GRB 050717: Swift-BAT refined analysis
  35. GRB050717: Swift XRT position
  36. Swift detection of GRB 050717
  37. Swift UVOT Observations of GRB 050716
  38. GRB050716: Refined analysis of the Swift-BAT burst
  39. GRB 050716: Lulin B and R band optical observations
  40. GRB050716, optical observation
  41. GRB 050716: Optical Observations
  42. GRB050716: Faulkes North Telescope observation
  43. GRB050715: Refined analysis of the Swift-BAT burst
  44. GRB 050715: Swift-BAT detection
  45. GRB 050713b: RTT150 optical observations
  46. GRB 050714B: optical afterglow
  47. Swift detection of a long transient (GRB 050714B?)
  48. GRB 050714, R-band candidate
  49. GRB 050714, optical observations
  50. GRB 050714A: ROTSE-III Optical Limits
  51. GRB 050713A: XRT refined analysis
  52. GRB 050709: Spectroscopy
  53. GRB 050713A: RAPTOR detection of early optical emission
  54. GRB050713B :Swift/UVOT observations
  55. GRB050712: TNG R-band observations
  56. GRB 050713B: Swift-BAT Refined Analysis
  57. GRB 050713A: Swift/UVOT observation
  58. GRB 050713A : Swift-BAT Refined Analysis
  59. GRB050712: Swift UVOT Observation of Afterglow Emission
  60. GRB 050713A XMM-Newton observation
  61. GRB050713B: Faulkes North Telescope observation
  62. GRB 050713B
  63. GRB050709 : Chandra source optical counterpart
  64. GRB050713: Liverpool Telescope prompt observations
  65. GRB 050712, optical observations
  66. GRB050709: Candidate X-ray Afterglow from Chandra
  67. GRB050713: possible I-band afterglow
  68. GRB 050713: Swift detection of Bright Burst
  69. GRB 050713A: ROTSE-III Optical Limits
  70. GRB050709: Radio Observations
  71. GRB 050709: Swift UVOT and XRT observations
  72. GRB 050712: Swift-BAT Refined Analysis
  73. GRB050712: UVOT candidate optical counterpart
  74. GRB 050712: Swift detection of a weak burst
  75. GRB 050709: LCO40 Observations
  76. PROMPT Rc Observations of GRB 050709
  77. GRB 050525a: PROMPT VRcIc Detections
  78. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  79. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  80. GRB 050626: Swift XRT observations
  81. GRB 050408: ARC 3.5-meter NIR Observations
  82. Swift UVOT observations of GRB 050701
  83. Swift trigger 143708 is really GRB 050701
  84. GRB 050607, radio observations
  85. GRB050525a: HST Observations
  86. XRF 050509c: Optical monitoring
  87. XRF050509c: Radio Detection
  88. GRB 050607 optical decay
  89. GRB050607: refined analysis of prompt REM observations
  90. Swift/UVOT observations of GRB050607
  91. GRB 050607: PROMPT VRcIc Observations
  92. GRB 050607: Optical decay and spectral slope
  93. GRB050607,optical observation
  94. GRB 050607 - XRT refined data analysis
  95. Optical Afterglow of GRB 050607
  96. GRB050607: Swift Detection of a long GRB
  97. GRB050607: prompt REM observations
  98. GRB 050603: prediction of t_break
  99. Limits on a SN in the field of GRB 050509b
  100. Konus-Wind observation of GRB 050603

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