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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"

26359 results found.

  1. Swift-BAT trigger 147918 is not a real GRB
  2. GRB050724: VLT observations of the variable source
  3. GRB050709: Second Epoch Chandra Observation
  4. GRB050726: Swift-BAT detection of a weak burst
  5. GRB 050724: Optical Variability in Nearby Galaxy
  6. GRB 050724: J-band observations
  7. GRB 050724: GMOS Imaging and Spectroscopy
  8. GRB050724: Radio Observation
  9. GRB 050724: Optical imaging/astrometry
  10. GRB 050724: Swift/UVOT Upper Limit
  11. GRB050724: Refined analysis of the Swift-BAT possible short burst
  12. GRB 050724: possible host galaxy in DSS
  13. GRB 050721A: Swift-BAT refined analysis
  14. GRB 050721A: Early Swift XRT analysis results
  15. GRB050721A: optical decay
  16. GRB 050721: optical afterglow confirmed
  17. GRB 050709: Refined Spectral and Temporal Properties
  18. GRB050714b: Radio Observation
  19. GRB050712: Radio Observations
  20. GRB050713a: Radio Observation
  21. GRB 050712, Tautenburg optical afterglow observations
  22. Swift-BAT detection of a possible GRB
  23. GRB 050714B: VLT R-band observations
  24. GRB 050717: Additional LCO observations
  25. GRB 050716; J-band observations
  26. GRB 050717: LCO near-IR observations
  27. Swift/UVOT Observations of GRB 050717
  28. GRB 050717: Swift-BAT refined analysis
  29. GRB050717: Swift XRT position
  30. Swift detection of GRB 050717
  31. Swift UVOT Observations of GRB 050716
  32. GRB 050716: Refined XRT analysis.
  33. GRB050716: Refined analysis of the Swift-BAT burst
  34. GRB 050716: Lulin B and R band optical observations
  35. GRB050716, optical observation
  36. GRB050716: Faulkes North Telescope observation
  37. GRB050715: Refined analysis of the Swift-BAT burst
  38. GRB 050715: Swift-BAT detection
  39. GRB 050713b: RTT150 optical observations
  40. GRB050714B: Refined analysis of the Swift-BAT burst
  41. GRB 050714B: optical afterglow
  42. GRB 050714, R-band candidate
  43. GRB 050714, optical observations
  44. GRB 050713A: XRT refined analysis
  45. GRB 050713A: RAPTOR detection of early optical emission
  46. GRB050713B :Swift/UVOT observations
  47. GRB050713b: XRT refined analysis
  48. GRB050712: TNG R-band observations
  49. GRB 050713B: Swift-BAT Refined Analysis
  50. GRB 050713A: Swift/UVOT observation
  51. GRB 050713A : Swift-BAT Refined Analysis
  52. GRB050712: Swift UVOT Observation of Afterglow Emission
  53. GRB 050713A : Lulin R-band observation
  54. GRB 050713A XMM-Newton observation
  55. GRB 050713b : Lulin R-band observations
  56. GRB050713B: Faulkes North Telescope observation
  57. RBO RI observations of GRB 050713A
  58. GRB 050713B
  59. GRB050709 : Chandra source optical counterpart
  60. GRB050713: Liverpool Telescope prompt observations
  61. GRB 050712, optical observations
  62. GRB050709: Candidate X-ray Afterglow from Chandra
  63. GRB050713: possible I-band afterglow
  64. GRB050712: XRT refined analysis
  65. GRB050709: Radio Observations
  66. GRB 050709: Swift UVOT and XRT observations
  67. GRB 050712: Swift-BAT Refined Analysis
  68. GRB050712: UVOT candidate optical counterpart
  69. GRB 050709: LCO40 Observations
  70. GRB050709, optical observations
  71. PROMPT Rc Observations of GRB 050709
  72. GRB 050525a: PROMPT VRcIc Detections
  73. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  74. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  75. GRB 050626: Swift XRT observations
  76. GRB 050408: ARC 3.5-meter NIR Observations
  77. GRB 050701: Refined XRT analysis
  78. Swift UVOT observations of GRB 050701
  79. GRB050701: Swift-BAT Refined analysis
  80. Swift trigger 143708 is really GRB 050701
  81. GRB 050607, radio observations
  82. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  83. GRB050525a: HST Observations
  84. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  85. XRF 050509c: Optical monitoring
  86. Konus-Wind observation of an intermediate burst from SGR 1806-20
  87. XRF050509c: Radio Detection
  88. GRB 050607 optical decay
  89. GRB050607: refined analysis of prompt REM observations
  90. GRB 050607: PROMPT VRcIc Observations
  91. GRB 050607: Optical decay and spectral slope
  92. GRB050607,optical observation
  93. Optical Afterglow of GRB 050607
  94. GRB050607: Swift Detection of a long GRB
  95. GRB050607: prompt REM observations
  96. Limits on a SN in the field of GRB 050509b
  97. GRB 050603 - XRT data analysis of the first day
  98. GRB050603, submillimetre observations
  99. GRB050603: Radio Detection
  100. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst

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