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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"

23404 results found.

  1. GRB 050803: early Swift XRT analysis results
  2. GRB 050803: TAROT optical limits
  3. GRB050803: Swift-BAT detection of a very long burst
  4. GCN GRB observation 050713A
  5. GRB 050802: Swift/UVOT optical and UV detections
  6. GRB050802 radio non-detection
  7. GRB 050730: OHP optical observations
  8. GRB 050802: Swift/UVOT observations
  9. GRB 050802 : Lulin Optical follow-up observation
  10. GRB 050802: Swift-BAT refined analysis
  11. GRB050801: Optical photometry and decay index
  12. GRB 050802: Swift Gamma-ray Burst
  13. GCN 050801: early Swift XRT analysis results
  14. GRB 050801: Swift-BAT refined analysis
  15. GRB050801: Swift-BAT detection of a burst
  16. GRB 050730: early TAROT optical observations
  17. GRB 050726: PROMPT Rc Observations
  18. Swift/UVOT photometry of GRB050730
  19. GRB 050730, spectra and optical photometry
  20. GRB050730: Refined BAT analysis of the Swift-BAT burst
  21. GRB 050730: Swift XRT afterglow observations
  22. GRB 050730 XMM-Newton observation
  23. GRB 050730: PROMPT VRcIc Observations
  24. GRB050730: Swift-BAT detection of a weak burst
  25. GRB 050709: PROMPT Rc Observations
  26. GRB 050724: Secure Host Redshift from Keck
  27. GRB050726: Swift UVOT observations
  28. GRB 050724: Chandra Observations of the X-ray Afterglow
  29. GRB050713: analysis of the XMM-Newton observation
  30. GRB050709: Second Epoch Chandra Observation
  31. GRB050709: Second Epoch Chandra Observation
  32. GRB 050726: early Swift XRT analysis results
  33. GRB050726: Swift-BAT detection of a weak burst
  34. GRB 050724: Optical Variability in Nearby Galaxy
  35. GRB 050724: J-band observations
  36. GRB 050724: GMOS Imaging and Spectroscopy
  37. GRB 050724: SWIFT XRT refined position
  38. RXTE ASM Detection of GRB050724
  39. GRB050724: Radio Observation
  40. GRB 050724: Optical limit
  41. GRB 050724: Swift/UVOT Upper Limit
  42. GRB050724: Refined analysis of the Swift-BAT possible short burst
  43. GRB 050724: possible host galaxy in DSS
  44. GRB050724: a short-burst detected by Swift
  45. GRB 050721A: Swift-BAT refined analysis
  46. GRB050721A: optical decay
  47. GRB 050721: optical afterglow confirmed
  48. GRB050721A: Swift-BAT detection of a weak burst
  49. GRB 050717: PROMPT RcIc Observations
  50. GRB050714b: Radio Observation
  51. GRB050712: Radio Observations
  52. GRB050713a: Radio Observation
  53. Swift-BAT trigger 146731 is not a real GRB
  54. GRB 050712, Tautenburg optical afterglow observations
  55. Swift-BAT detection of a possible GRB
  56. GRB 050714B: VLT R-band observations
  57. GRB 050717: Additional LCO observations
  58. GRB 050716; J-band observations
  59. GRB 050717: LCO near-IR observations
  60. Swift/UVOT Observations of GRB 050717
  61. GRB 050717: Swift-BAT refined analysis
  62. GRB050717: Swift XRT position
  63. Swift detection of GRB 050717
  64. Swift UVOT Observations of GRB 050716
  65. GRB050716: Refined analysis of the Swift-BAT burst
  66. GRB 050716: Lulin B and R band optical observations
  67. GRB050716, optical observation
  68. GRB 050716: Optical Observations
  69. GRB050716: Faulkes North Telescope observation
  70. GRB050715: Refined analysis of the Swift-BAT burst
  71. GRB 050715: Swift-BAT detection
  72. GRB 050713b: RTT150 optical observations
  73. GRB 050714B: optical afterglow
  74. Swift detection of a long transient (GRB 050714B?)
  75. GRB 050714, R-band candidate
  76. GRB 050714, optical observations
  77. GRB 050714A: ROTSE-III Optical Limits
  78. GRB 050713A: XRT refined analysis
  79. GRB 050709: Spectroscopy
  80. GRB 050713A: RAPTOR detection of early optical emission
  81. GRB050713B :Swift/UVOT observations
  82. GRB050712: TNG R-band observations
  83. GRB 050713B: Swift-BAT Refined Analysis
  84. GRB 050713A: Swift/UVOT observation
  85. GRB 050713A : Swift-BAT Refined Analysis
  86. GRB050712: Swift UVOT Observation of Afterglow Emission
  87. GRB 050713A XMM-Newton observation
  88. GRB050713B: Faulkes North Telescope observation
  89. GRB 050713B
  90. GRB050709 : Chandra source optical counterpart
  91. GRB050713: Liverpool Telescope prompt observations
  92. GRB 050712, optical observations
  93. GRB050709: Candidate X-ray Afterglow from Chandra
  94. GRB050713: possible I-band afterglow
  95. GRB 050713: Swift detection of Bright Burst
  96. GRB 050713A: ROTSE-III Optical Limits
  97. GRB050709: Radio Observations
  98. GRB 050709: Swift UVOT and XRT observations
  99. GRB 050712: Swift-BAT Refined Analysis
  100. GRB050712: UVOT candidate optical counterpart

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