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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').
  1. GRB 050716; J-band observations
  2. Konus-Wind observation of GRB 050717
  3. GRB 050717: LCO near-IR observations
  4. Swift/UVOT Observations of GRB 050717
  5. GRB 050717: Swift-BAT refined analysis
  6. GRB 050717: Refined XRT analysis.
  7. GRB050712: optical limits
  8. GRB050717: Swift XRT position
  9. Swift detection of GRB 050717
  10. GRB 050716 - UKIRT identification of candidate afterglow
  11. Swift UVOT Observations of GRB 050716
  12. GRB 050716: Refined XRT analysis.
  13. GRB050716: Refined analysis of the Swift-BAT burst
  14. GRB 050716: Lulin B and R band optical observations
  15. GRB050716, optical observation
  16. GRB 050716: Optical Observations
  17. GRB050716: Faulkes North Telescope observation
  18. GRB050716: Correction to sign in XRT coordinate
  19. Swift/BAT detection of GRB 050716
  20. GRB050715: Refined analysis of the Swift-BAT burst
  21. GRB 050715: Swift-BAT detection
  22. Swift UVOT Observations of GRB 050714B
  23. Konus-Wind observation of GRB 050713A
  24. GRB 050714B: refined XRT analysis
  25. GRB 050713b: RTT150 optical observations
  26. GRB 050714B: candidate afterglow does not fade
  27. GRB050714B: Refined analysis of the Swift-BAT burst
  28. GRB 050714B: optical afterglow
  29. Swift detection of a long transient (GRB 050714B?)
  30. GRB 050709: optical afterglow candidate
  31. GRB 050714, R-band candidate
  32. GRB 050714: Swift XRT afterglow position
  33. GRB 050714, optical observations
  34. GRB 050714A: ROTSE-III Optical Limits
  35. GRB 050714 - A long GRB detected with INTEGRAL
  36. GRB 050713A: XRT refined analysis
  37. GRB 050709: Spectroscopy
  38. GRB 050713A: RAPTOR detection of early optical emission
  39. GRB050713B :Swift/UVOT observations
  40. GRB050713b: XRT refined analysis
  41. GRB050712: TNG R-band observations
  42. GRB 050713B: Swift-BAT Refined Analysis
  43. Swift-BAT Trigger 145729 is not a GRB
  44. GRB 050713A: Swift/UVOT observation
  45. GRB 050713A : Swift-BAT Refined Analysis
  46. GRB050712: Swift UVOT Observation of Afterglow Emission
  47. GRB 050713A : Lulin R-band observation
  48. GRB 050713A XMM-Newton observation
  49. GRB 050713b : Lulin R-band observations
  50. GRB050713B: Faulkes North Telescope observation
  51. RBO RI observations of GRB 050713A
  52. GRB 050713B
  53. GRB050709 : Chandra source optical counterpart
  54. GRB050713: Liverpool Telescope prompt observations
  55. GRB 050712, optical observations
  56. GRB 050713 : Planned XMM-Newton observation
  57. GRB050709: Candidate X-ray Afterglow from Chandra
  58. GRB 050713, R-band observations at NOT
  59. GRB 050713: ARC NIR Detections and Identification of Fading
  60. GRB050713: possible I-band afterglow
  61. GRB 050713: Swift detection of Bright Burst
  62. GRB 050713A: ROTSE-III Optical Limits
  63. GRB050712: XRT refined analysis
  64. GRB050709: Radio Observations
  65. GRB 050709: Swift UVOT and XRT observations
  66. GRB 050712: Swift-BAT Refined Analysis
  67. GRB050712: UVOT candidate optical counterpart
  68. GRB 050712: Swift XRT afterglow position
  69. GRB 050712: Swift detection of a weak burst
  70. GRB 050709: LCO40 Observations
  71. GRB050709, optical observations
  72. GRB050709: A Possible Short-Hard GRB Localized by HETE
  73. PROMPT Rc Observations of GRB 050709
  74. GRB 050525a: PROMPT VRcIc Detections
  75. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  76. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  77. GRB 050626 optical observations
  78. GRB 050626: Swift XRT observations
  79. GRB 050701
  80. GRB 050701, optical observations
  81. GRB 050408: ARC 3.5-meter NIR Observations
  82. GRB 050701: Refined XRT analysis
  83. Swift UVOT observations of GRB 050701
  84. GRB050701: Swift-BAT Refined analysis
  85. GRB 050701: Swift XRT afterglow position
  86. Swift trigger 143708 is really GRB 050701
  87. GRB 050607, radio observations
  88. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  89. GRB 050626 - Correction to GCN 3552
  90. GRB 050626 - a long GRB detected with INTEGRAL
  91. GRB 050525A: Swift Late-Time Decay Rate
  92. GRB050525a: HST Observations
  93. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  94. H3804: A Possible New XRB Detected by HETE
  95. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  96. XRF 050509c: Optical monitoring
  97. Konus-Wind observation of an intermediate burst from SGR 1806-20
  98. IBAS Alert #2512 is NOT a GRB
  99. XRF050509c: Radio Detection
  100. GRB 050416(a): Host Galaxy Redshift Determination

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