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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"

28083 results found.

  1. GRB 050803: TAROT optical limits
  2. GCN GRB observation 050713A
  3. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  4. GRB050802 radio non-detection
  5. GRB 050730: OHP optical observations
  6. GRB 050802: early Swift XRT analysis results
  7. GRB 050802: Swift/UVOT observations
  8. GRB 050802: Swift-BAT refined analysis
  9. GRB050801: Optical photometry and decay index
  10. GRB 050802: Swift Gamma-ray Burst
  11. GRB050801: Swift/UVOT Optical and UV detections
  12. GRB 050730: Preliminary Analysis of MIKE Spectrum
  13. GCN 050801: early Swift XRT analysis results
  14. GRB 050801: Swift-BAT refined analysis
  15. GRB 050730: XRT refined analysis
  16. GRB 050730: early TAROT optical observations
  17. GRB 050730, spectra and optical photometry
  18. GRB050730: Refined BAT analysis of the Swift-BAT burst
  19. GRB 050730 XMM-Newton observation
  20. GRB050730: Swift-BAT detection of a weak burst
  21. GRB050713b: Maidanak optical observations
  22. GRB 050724: Secure Host Redshift from Keck
  23. GRB 050724: WHT optical observations
  24. GRB050713: analysis of the XMM-Newton observation
  25. Swift-BAT trigger 147918 is not a real GRB
  26. GRB050724: VLT observations of the variable source
  27. GRB050709: Second Epoch Chandra Observation
  28. GRB050726: Swift-BAT detection of a weak burst
  29. GRB 050724: Optical Variability in Nearby Galaxy
  30. GRB 050724: J-band observations
  31. GRB 050724: GMOS Imaging and Spectroscopy
  32. GRB050724: Radio Observation
  33. GRB 050724: Optical imaging/astrometry
  34. GRB 050724: Swift/UVOT Upper Limit
  35. GRB050724: Refined analysis of the Swift-BAT possible short burst
  36. GRB 050724: possible host galaxy in DSS
  37. GRB 050721A: Swift-BAT refined analysis
  38. GRB 050721A: Early Swift XRT analysis results
  39. GRB050721A: optical decay
  40. GRB 050721: optical afterglow confirmed
  41. GRB 050709: Refined Spectral and Temporal Properties
  42. GRB050714b: Radio Observation
  43. GRB050712: Radio Observations
  44. GRB050713a: Radio Observation
  45. GRB 050712, Tautenburg optical afterglow observations
  46. Swift-BAT detection of a possible GRB
  47. GRB 050714B: VLT R-band observations
  48. GRB 050717: Additional LCO observations
  49. GRB 050716; J-band observations
  50. GRB 050717: LCO near-IR observations
  51. Swift/UVOT Observations of GRB 050717
  52. GRB 050717: Swift-BAT refined analysis
  53. GRB050717: Swift XRT position
  54. Swift detection of GRB 050717
  55. Swift UVOT Observations of GRB 050716
  56. GRB 050716: Refined XRT analysis.
  57. GRB050716: Refined analysis of the Swift-BAT burst
  58. GRB 050716: Lulin B and R band optical observations
  59. GRB050716, optical observation
  60. GRB050716: Faulkes North Telescope observation
  61. GRB050715: Refined analysis of the Swift-BAT burst
  62. GRB 050715: Swift-BAT detection
  63. GRB 050713b: RTT150 optical observations
  64. GRB050714B: Refined analysis of the Swift-BAT burst
  65. GRB 050714B: optical afterglow
  66. GRB 050714, R-band candidate
  67. GRB 050714, optical observations
  68. GRB 050713A: XRT refined analysis
  69. GRB 050713A: RAPTOR detection of early optical emission
  70. GRB050713B :Swift/UVOT observations
  71. GRB050713b: XRT refined analysis
  72. GRB050712: TNG R-band observations
  73. GRB 050713B: Swift-BAT Refined Analysis
  74. GRB 050713A: Swift/UVOT observation
  75. GRB 050713A : Swift-BAT Refined Analysis
  76. GRB050712: Swift UVOT Observation of Afterglow Emission
  77. GRB 050713A : Lulin R-band observation
  78. GRB 050713A XMM-Newton observation
  79. GRB 050713b : Lulin R-band observations
  80. GRB050713B: Faulkes North Telescope observation
  81. RBO RI observations of GRB 050713A
  82. GRB 050713B
  83. GRB050709 : Chandra source optical counterpart
  84. GRB050713: Liverpool Telescope prompt observations
  85. GRB 050712, optical observations
  86. GRB050709: Candidate X-ray Afterglow from Chandra
  87. GRB050713: possible I-band afterglow
  88. GRB050712: XRT refined analysis
  89. GRB050709: Radio Observations
  90. GRB 050709: Swift UVOT and XRT observations
  91. GRB 050712: Swift-BAT Refined Analysis
  92. GRB050712: UVOT candidate optical counterpart
  93. GRB 050709: LCO40 Observations
  94. GRB050709, optical observations
  95. PROMPT Rc Observations of GRB 050709
  96. GRB 050525a: PROMPT VRcIc Detections
  97. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  98. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  99. GRB 050626: Swift XRT observations
  100. GRB 050408: ARC 3.5-meter NIR Observations

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