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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. GRB050712: TNG R-band observations
  2. GRB 050713B: Swift-BAT Refined Analysis
  3. Swift-BAT Trigger 145729 is not a GRB
  4. GRB 050713A: Swift/UVOT observation
  5. GRB 050713A : Swift-BAT Refined Analysis
  6. GRB050712: Swift UVOT Observation of Afterglow Emission
  7. GRB 050713A : Lulin R-band observation
  8. GRB 050713A XMM-Newton observation
  9. GRB 050713b : Lulin R-band observations
  10. GRB050713B: Faulkes North Telescope observation
  11. RBO RI observations of GRB 050713A
  12. GRB 050713B
  13. GRB050709 : Chandra source optical counterpart
  14. GRB050713: Liverpool Telescope prompt observations
  15. GRB 050712, optical observations
  16. GRB 050713 : Planned XMM-Newton observation
  17. GRB050709: Candidate X-ray Afterglow from Chandra
  18. GRB 050713, R-band observations at NOT
  19. GRB 050713: ARC NIR Detections and Identification of Fading
  20. GRB050713: possible I-band afterglow
  21. GRB 050713: Swift detection of Bright Burst
  22. GRB 050713A: ROTSE-III Optical Limits
  23. GRB050712: XRT refined analysis
  24. GRB050709: Radio Observations
  25. GRB 050709: Swift UVOT and XRT observations
  26. GRB 050712: Swift-BAT Refined Analysis
  27. GRB050712: UVOT candidate optical counterpart
  28. GRB 050712: Swift XRT afterglow position
  29. GRB 050712: Swift detection of a weak burst
  30. GRB 050709: LCO40 Observations
  31. GRB050709, optical observations
  32. GRB050709: A Possible Short-Hard GRB Localized by HETE
  33. PROMPT Rc Observations of GRB 050709
  34. GRB 050525a: PROMPT VRcIc Detections
  35. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  36. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  37. GRB 050626 optical observations
  38. GRB 050626: Swift XRT observations
  39. GRB 050701
  40. GRB 050701, optical observations
  41. GRB 050408: ARC 3.5-meter NIR Observations
  42. GRB 050701: Refined XRT analysis
  43. Swift UVOT observations of GRB 050701
  44. GRB050701: Swift-BAT Refined analysis
  45. GRB 050701: Swift XRT afterglow position
  46. Swift trigger 143708 is really GRB 050701
  47. GRB 050607, radio observations
  48. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  49. GRB 050626 - Correction to GCN 3552
  50. GRB 050626 - a long GRB detected with INTEGRAL
  51. GRB 050525A: Swift Late-Time Decay Rate
  52. GRB050525a: HST Observations
  53. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  54. H3804: A Possible New XRB Detected by HETE
  55. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  56. XRF 050509c: Optical monitoring
  57. Konus-Wind observation of an intermediate burst from SGR 1806-20
  58. IBAS Alert #2512 is NOT a GRB
  59. XRF050509c: Radio Detection
  60. GRB 050416(a): Host Galaxy Redshift Determination
  61. GRB 050607: MDM Observation
  62. GRB 050607 optical decay
  63. GRB 050607: RTT150 optical observations
  64. GRB050607: refined analysis of prompt REM observations
  65. Swift/UVOT observations of GRB050607
  66. GRB 050607 : Lulin R-band observation
  67. GRB 050607: PROMPT VRcIc Observations
  68. GRB 050607: RAPTOR-S Early Optical Limits
  69. GRB050607: KAIT optical limits
  70. GRB 050525a, Mid-Infrared Observations
  71. GRB 050607: Optical decay and spectral slope
  72. GRB 050607: MDM Observations
  73. GRB050607,optical observation
  74. GRB 050607 - XRT refined data analysis
  75. Optical Afterglow of GRB 050607
  76. GRB050607 optical limit by "Pi of the Sky"
  77. GRB050607: Swift Detection of a long GRB
  78. GRB050607: P60 Observations
  79. GRB050607: prompt REM observations
  80. GRB 050603: prediction of t_break
  81. Limits on a SN in the field of GRB 050509b
  82. GRB 050603: Redshift
  83. GRB 050603 - XRT data analysis of the first day
  84. Konus-Wind observation of GRB 050603
  85. GRB 050603: Analysis of UVOT data
  86. GRB050603: Fading Afterglow observed by Swift UVOT
  87. GRB050603, submillimetre observations
  88. GRB 050603: Swift XRT Position
  89. GRB050603: Radio Detection
  90. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  91. GRB 050603: Afterglow Identification from LCO
  92. GRB 050603: INTEGRAL shows it is not a short GRB
  93. Swift/BAT Detection of GRB050603
  94. GRB 050408: jet break in the XRT light curve
  95. GRB 050525a, infrared observations
  96. GRB 050525a, SMARTS optical/IR afterglow observations
  97. GRB050528, XRT observations
  98. Correction to GCN Circ 3502 on GRB 050528
  99. GRB050528: updated Liverpool Telescope limits
  100. Swift-BAT GRB 050528: a soft burst

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