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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20958 results found.

  1. GRB 050730: XRT refined analysis
  2. GRB 050730: early TAROT optical observations
  3. GRB 050726: PROMPT Rc Observations
  4. GRB 050730: RTT150 optical observations
  5. GRB 050730, spectra and optical photometry
  6. GRB 050730: Swift XRT afterglow observations
  7. GRB 050730: PROMPT VRcIc Observations
  8. GRB050730, afterglow observations
  9. GRB050730: confirmation of redshift
  10. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  11. GRB 050730, SMARTS optical/IR afterglow observations
  12. GRB050730: Liverpool Telescope optical observations
  13. GRB050730: Swift-BAT detection of a weak burst
  14. GRB 050713A: Swift XRT extended light curve
  15. GRB 050709: PROMPT Rc Observations
  16. GRB050713b: Maidanak optical observations
  17. GRB 050724: WHT optical observations
  18. GRB050726: Swift UVOT observations
  19. GRB 050724: Chandra Observations of the X-ray Afterglow
  20. GRB050724: Refined Radio Position
  21. GRB 050724, SMARTS optical/IR afterglow observations
  22. GRB 050726, SMARTS optical/IR observations
  23. GRB 050727: RTT150 optical observations
  24. GRB050724: VLT observations of the variable source
  25. GRB 050726: PROMPT Rc Observations
  26. GRB050724: Further Radio Observations
  27. GRB 050726: early Swift XRT analysis results
  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: spectroscopy of object in the XRT error circle
  34. GRB 050724: optical and near-IR observations
  35. GRB 050724: Optical imaging/astrometry
  36. GRB 050724: RTT150 optical observations
  37. GRB 050724 : Lulin early R-band monitoring observations
  38. GRB 050721: early afterglow light curve
  39. GRB 050721: optical afterglow confirmed
  40. GRB 050721a: Optical Observations
  41. GRB 050717: PROMPT RcIc Observations
  42. GRB050712: Radio Observations
  43. GRB 050712, Tautenburg optical afterglow observations
  44. Swift-BAT detection of a possible GRB
  45. GRB 050714B: VLT R-band observations
  46. GRB 050717: Additional LCO observations
  47. GRB 050716; J-band observations
  48. GRB 050717: LCO near-IR observations
  49. Swift/UVOT Observations of GRB 050717
  50. GRB 050717: Refined XRT analysis.
  51. Swift detection of GRB 050717
  52. GRB 050716 - UKIRT identification of candidate afterglow
  53. Swift UVOT Observations of GRB 050716
  54. GRB 050716: Refined XRT analysis.
  55. GRB 050716: Lulin B and R band optical observations
  56. GRB 050716: Optical Observations
  57. GRB050716: Faulkes North Telescope observation
  58. Swift/BAT detection of GRB 050716
  59. Swift UVOT Observations of GRB 050714B
  60. GRB 050714B: refined XRT analysis
  61. GRB 050713b: RTT150 optical observations
  62. Swift detection of a long transient (GRB 050714B?)
  63. GRB 050714, optical observations
  64. GRB 050709: Spectroscopy
  65. GRB050713B :Swift/UVOT observations
  66. GRB050712: TNG R-band observations
  67. GRB050712: Swift UVOT Observation of Afterglow Emission
  68. GRB 050713A : Lulin R-band observation
  69. GRB 050713b : Lulin R-band observations
  70. GRB050713B: Faulkes North Telescope observation
  71. RBO RI observations of GRB 050713A
  72. GRB 050713B
  73. GRB050713: Liverpool Telescope prompt observations
  74. GRB 050712, optical observations
  75. GRB050709: Candidate X-ray Afterglow from Chandra
  76. GRB 050713, R-band observations at NOT
  77. GRB 050713: ARC NIR Detections and Identification of Fading
  78. GRB 050713: Swift detection of Bright Burst
  79. GRB050709: Radio Observations
  80. GRB 050709: Swift UVOT and XRT observations
  81. GRB 050712: Swift detection of a weak burst
  82. GRB 050709: LCO40 Observations
  83. GRB050709, optical observations
  84. PROMPT Rc Observations of GRB 050709
  85. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  86. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  87. GRB 050626 optical observations
  88. GRB 050626: Swift XRT observations
  89. GRB 050701, optical observations
  90. GRB 050408: ARC 3.5-meter NIR Observations
  91. Swift UVOT observations of GRB 050701
  92. GRB 050607, radio observations
  93. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  94. GRB 050525A: Swift Late-Time Decay Rate
  95. GRB050525a: HST Observations
  96. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  97. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  98. XRF 050509c: Optical monitoring
  99. XRF050509c: Radio Detection
  100. GRB 050416(a): Host Galaxy Redshift Determination

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