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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"

15685 results found.

  1. GRB050801: Unchanged decay slope
  2. GRB 050730: OHP optical observations
  3. GRB 050802 : Lulin Optical follow-up observation
  4. GRB050801: Optical photometry and decay index
  5. GRB050801: Swift/UVOT Optical and UV detections
  6. GRB 050801, SMARTS optical/IR afterglow observations
  7. GRB 050801: ROTSE-III Early Afterglow Break
  8. GRB 050730: early TAROT optical observations
  9. GRB 050730: RTT150 optical observations
  10. GRB 050730, spectra and optical photometry
  11. GRB 050730: Swift XRT afterglow observations
  12. GRB050730, afterglow observations
  13. GRB050730: confirmation of redshift
  14. GRB 050730, SMARTS optical/IR afterglow observations
  15. GRB050730: Liverpool Telescope optical observations
  16. GRB 050730, optical candidate
  17. GRB050730: Swift-BAT detection of a weak burst
  18. GRB 050713A: Swift XRT extended light curve
  19. GRB050713b: Maidanak optical observations
  20. GRB 050724: WHT optical observations
  21. GRB050726: Swift UVOT observations
  22. GRB050724: Refined Radio Position
  23. GRB 050724, SMARTS optical/IR afterglow observations
  24. GRB 050726, SMARTS optical/IR observations
  25. GRB 050727: RTT150 optical observations
  26. GRB050727: KAIT optical limit
  27. GRB050709: Second Epoch Chandra Observation
  28. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  29. GRB050724: Further Radio Observations
  30. GRB050726: Swift-BAT detection of a weak burst
  31. GRB 050724: Optical Variability in Nearby Galaxy
  32. GRB 050724: Optical limit
  33. GRB 050724: optical and near-IR observations
  34. GRB 050724: Optical imaging/astrometry
  35. GRB 050724: RTT150 optical observations
  36. GRB 050724: early Swift XRT analysis results
  37. GRB050721A: optical decay
  38. GRB 050721: optical afterglow confirmed
  39. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  40. GRB 050721a: Optical Observations
  41. GRB 050709: Refined Spectral and Temporal Properties
  42. GRB050712: Radio Observations
  43. GRB050713a: Radio Observation
  44. GRB 050712, Tautenburg optical afterglow observations
  45. Swift-BAT detection of a possible GRB
  46. GRB050712: optical limits
  47. Swift detection of GRB 050717
  48. GRB 050716: Lulin B and R band optical observations
  49. GRB050716, optical observation
  50. GRB 050716: Optical Observations
  51. Swift/BAT detection of GRB 050716
  52. GRB 050713b: RTT150 optical observations
  53. GRB 050714B: candidate afterglow does not fade
  54. GRB 050714B: optical afterglow
  55. Swift detection of a long transient (GRB 050714B?)
  56. GRB 050709: optical afterglow candidate
  57. GRB 050714, optical observations
  58. GRB 050714A: ROTSE-III Optical Limits
  59. GRB 050709: Spectroscopy
  60. GRB 050713A: RAPTOR detection of early optical emission
  61. GRB050712: Swift UVOT Observation of Afterglow Emission
  62. GRB 050713B
  63. GRB050709 : Chandra source optical counterpart
  64. GRB 050712, optical observations
  65. GRB050709: Candidate X-ray Afterglow from Chandra
  66. GRB 050713, R-band observations at NOT
  67. GRB 050713: Swift detection of Bright Burst
  68. GRB 050713A: ROTSE-III Optical Limits
  69. GRB 050709: Swift UVOT and XRT observations
  70. GRB050712: UVOT candidate optical counterpart
  71. GRB 050712: Swift detection of a weak burst
  72. GRB050709, optical observations
  73. GRB050709: A Possible Short-Hard GRB Localized by HETE
  74. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  75. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  76. GRB 050626 optical observations
  77. GRB 050626: Swift XRT observations
  78. GRB 050701, optical observations
  79. GRB 050607, radio observations
  80. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  81. GRB 050525A: Swift Late-Time Decay Rate
  82. H3804: A Possible New XRB Detected by HETE
  83. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  84. XRF 050509c: Optical monitoring
  85. XRF050509c: Radio Detection
  86. GRB 050607 optical decay
  87. GRB 050607: RTT150 optical observations
  88. GRB050607: refined analysis of prompt REM observations
  89. Swift/UVOT observations of GRB050607
  90. GRB 050607: RAPTOR-S Early Optical Limits
  91. GRB050607: KAIT optical limits
  92. GRB 050525a, Mid-Infrared Observations
  93. GRB 050607: Optical decay and spectral slope
  94. GRB 050607: MDM Observations
  95. GRB050607,optical observation
  96. GRB 050607 - XRT refined data analysis
  97. Optical Afterglow of GRB 050607
  98. GRB050607 optical limit by "Pi of the Sky"
  99. GRB050607: prompt REM observations
  100. GRB050603: Fading Afterglow observed by Swift UVOT

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