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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"

28085 results found.

  1. GRB 050802.422: Fading of the afterglow and detection of the host
  2. GRB 050803: early Swift XRT analysis results
  3. GRB 050803: TAROT optical limits
  4. GCN GRB observation 050713A
  5. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  6. GRB050802 radio non-detection
  7. GRB 050730: OHP optical observations
  8. GRB 050802: early Swift XRT analysis results
  9. GRB 050802: Swift/UVOT observations
  10. GRB 050802: Swift-BAT refined analysis
  11. GRB050801: Optical photometry and decay index
  12. GRB 050802: Swift Gamma-ray Burst
  13. GRB050801: Swift/UVOT Optical and UV detections
  14. GRB 050730: Preliminary Analysis of MIKE Spectrum
  15. GCN 050801: early Swift XRT analysis results
  16. GRB 050801: Swift-BAT refined analysis
  17. GRB 050730: XRT refined analysis
  18. GRB 050730: early TAROT optical observations
  19. GRB 050730, spectra and optical photometry
  20. GRB050730: Refined BAT analysis of the Swift-BAT burst
  21. GRB 050730 XMM-Newton observation
  22. GRB050730: Swift-BAT detection of a weak burst
  23. GRB050713b: Maidanak optical observations
  24. GRB 050724: Secure Host Redshift from Keck
  25. GRB 050724: WHT optical observations
  26. GRB050713: analysis of the XMM-Newton observation
  27. Swift-BAT trigger 147918 is not a real GRB
  28. GRB050724: VLT observations of the variable source
  29. GRB050709: Second Epoch Chandra Observation
  30. GRB050726: Swift-BAT detection of a weak burst
  31. GRB 050724: Optical Variability in Nearby Galaxy
  32. GRB 050724: J-band observations
  33. GRB 050724: GMOS Imaging and Spectroscopy
  34. GRB050724: Radio Observation
  35. GRB 050724: Optical imaging/astrometry
  36. GRB 050724: Swift/UVOT Upper Limit
  37. GRB050724: Refined analysis of the Swift-BAT possible short burst
  38. GRB 050724: possible host galaxy in DSS
  39. GRB 050721A: Swift-BAT refined analysis
  40. GRB 050721A: Early Swift XRT analysis results
  41. GRB050721A: optical decay
  42. GRB 050721: optical afterglow confirmed
  43. GRB 050709: Refined Spectral and Temporal Properties
  44. GRB050714b: Radio Observation
  45. GRB050712: Radio Observations
  46. GRB050713a: Radio Observation
  47. GRB 050712, Tautenburg optical afterglow observations
  48. Swift-BAT detection of a possible GRB
  49. GRB 050714B: VLT R-band observations
  50. GRB 050717: Additional LCO observations
  51. GRB 050716; J-band observations
  52. GRB 050717: LCO near-IR observations
  53. Swift/UVOT Observations of GRB 050717
  54. GRB 050717: Swift-BAT refined analysis
  55. GRB050717: Swift XRT position
  56. Swift detection of GRB 050717
  57. Swift UVOT Observations of GRB 050716
  58. GRB 050716: Refined XRT analysis.
  59. GRB050716: Refined analysis of the Swift-BAT burst
  60. GRB 050716: Lulin B and R band optical observations
  61. GRB050716, optical observation
  62. GRB050716: Faulkes North Telescope observation
  63. GRB050715: Refined analysis of the Swift-BAT burst
  64. GRB 050715: Swift-BAT detection
  65. GRB 050713b: RTT150 optical observations
  66. GRB050714B: Refined analysis of the Swift-BAT burst
  67. GRB 050714B: optical afterglow
  68. GRB 050714, R-band candidate
  69. GRB 050714, optical observations
  70. GRB 050713A: XRT refined analysis
  71. GRB 050713A: RAPTOR detection of early optical emission
  72. GRB050713B :Swift/UVOT observations
  73. GRB050713b: XRT refined analysis
  74. GRB050712: TNG R-band observations
  75. GRB 050713B: Swift-BAT Refined Analysis
  76. GRB 050713A: Swift/UVOT observation
  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. GRB050709: Candidate X-ray Afterglow from Chandra
  89. GRB050713: possible I-band afterglow
  90. GRB050712: XRT refined analysis
  91. GRB050709: Radio Observations
  92. GRB 050709: Swift UVOT and XRT observations
  93. GRB 050712: Swift-BAT Refined Analysis
  94. GRB050712: UVOT candidate optical counterpart
  95. GRB 050709: LCO40 Observations
  96. GRB050709, optical observations
  97. PROMPT Rc Observations of GRB 050709
  98. GRB 050525a: PROMPT VRcIc Detections
  99. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  100. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration

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