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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"

15986 results found.

  1. GRB050805b: CrAO optical limit
  2. GRB050805a : Null detection report
  3. GRB050730, optical observations
  4. GRB050803, optical observations
  5. GRB 050805b: OHP optical limits
  6. GRB 050805b: TAROT optical limits
  7. GRB050805b: MASTER optical observations
  8. GRB050805a: MASTER optical candidat
  9. GRB050802: TNG optical observations
  10. GRB050803: Radio Observation
  11. GRB 050803: RTT150 optical observations
  12. GRB050801: Radio Observation
  13. GRB050730: Radio Detection
  14. GRB050803: CrAO optical observations, possible OT candidate
  15. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  16. GRB 050802.422: Fading of the afterglow and detection of the host
  17. GRB050803: MASTER further analys
  18. GRB 050803, optical observations
  19. GRB 050803: TAROT optical limits
  20. GRB050803: MASTER optical observations
  21. GRB050802: Tentative absorption redshift
  22. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  23. GRB 050802: Swift/UVOT optical and UV detections
  24. GRB050802: CrAO optical observations
  25. GRB050801: Unchanged decay slope
  26. GRB 050730: OHP optical observations
  27. GRB 050802 : Lulin Optical follow-up observation
  28. GRB050801: Optical photometry and decay index
  29. GRB050801: Swift/UVOT Optical and UV detections
  30. GRB 050801, SMARTS optical/IR afterglow observations
  31. GRB 050801: ROTSE-III Early Afterglow Break
  32. GRB 050730: early TAROT optical observations
  33. GRB 050730: RTT150 optical observations
  34. GRB 050730, spectra and optical photometry
  35. GRB 050730: Swift XRT afterglow observations
  36. GRB050730: confirmation of redshift
  37. GRB 050730, SMARTS optical/IR afterglow observations
  38. GRB050730: Liverpool Telescope optical observations
  39. GRB 050730, optical candidate
  40. GRB050730: Swift-BAT detection of a weak burst
  41. GRB050713b: Maidanak optical observations
  42. GRB 050724: WHT optical observations
  43. GRB050726: Swift UVOT observations
  44. GRB050724: Refined Radio Position
  45. GRB 050724, SMARTS optical/IR afterglow observations
  46. GRB 050726, SMARTS optical/IR observations
  47. GRB 050727: RTT150 optical observations
  48. GRB050727: KAIT optical limit
  49. GRB050709: Second Epoch Chandra Observation
  50. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  51. GRB050724: Further Radio Observations
  52. GRB050726: Swift-BAT detection of a weak burst
  53. GRB 050724: Optical Variability in Nearby Galaxy
  54. GRB 050724: Optical limit
  55. GRB 050724: optical and near-IR observations
  56. GRB 050724: Optical imaging/astrometry
  57. GRB 050724: RTT150 optical observations
  58. GRB 050724: early Swift XRT analysis results
  59. GRB050721A: optical decay
  60. GRB 050721: optical afterglow confirmed
  61. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  62. GRB 050721a: Optical Observations
  63. GRB 050709: Refined Spectral and Temporal Properties
  64. GRB050712: Radio Observations
  65. GRB050713a: Radio Observation
  66. GRB 050712, Tautenburg optical afterglow observations
  67. Swift-BAT detection of a possible GRB
  68. GRB050712: optical limits
  69. Swift detection of GRB 050717
  70. GRB 050716: Lulin B and R band optical observations
  71. GRB050716, optical observation
  72. GRB 050716: Optical Observations
  73. Swift/BAT detection of GRB 050716
  74. GRB 050713b: RTT150 optical observations
  75. GRB 050714B: candidate afterglow does not fade
  76. GRB 050714B: optical afterglow
  77. Swift detection of a long transient (GRB 050714B?)
  78. GRB 050709: optical afterglow candidate
  79. GRB 050714, optical observations
  80. GRB 050714A: ROTSE-III Optical Limits
  81. GRB 050709: Spectroscopy
  82. GRB 050713A: RAPTOR detection of early optical emission
  83. GRB050712: Swift UVOT Observation of Afterglow Emission
  84. GRB 050713B
  85. GRB050709 : Chandra source optical counterpart
  86. GRB 050712, optical observations
  87. GRB050709: Candidate X-ray Afterglow from Chandra
  88. GRB 050713, R-band observations at NOT
  89. GRB 050713: Swift detection of Bright Burst
  90. GRB 050713A: ROTSE-III Optical Limits
  91. GRB 050709: Swift UVOT and XRT observations
  92. GRB050712: UVOT candidate optical counterpart
  93. GRB 050712: Swift detection of a weak burst
  94. GRB050709, optical observations
  95. GRB050709: A Possible Short-Hard GRB Localized by HETE
  96. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  97. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  98. GRB 050626 optical observations
  99. GRB 050626: Swift XRT observations
  100. GRB 050701, optical observations

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