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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"

18485 results found.

  1. GRB 050820: Early RAPTOR detections
  2. GRB050819: refined XRT analysis
  3. GRB 050820: Swift detection of a GRB
  4. GRB050819: Swift XRT position
  5. GRB050819: Swift-BAT detection of a weak burst
  6. GRB 050817: Optical observations
  7. GRB 050814: continued fading
  8. GRB050815: XRT refined analysis
  9. GRB 050815: ROTSE-III Optical Limits
  10. GRB050815: Swift XRT afterglow localization
  11. GRB050815: Swift-BAT detection of a burst
  12. GRB050814: Fading red source
  13. GRB050814: P60 Optical Afterglow Candidate
  14. GRB 050813: Non-fading of afterglow candidate
  15. GRB 050814: XRT refined analysis
  16. GRB050814: SWIFT/UVOT observation
  17. GRB 050814: Swift XRT Afterglow Localization
  18. GRB 050814: Swift detection of a burst
  19. GRB 050813: Magellan detection of a high redshift galaxy cluster
  20. GRB050813, SDSS pre-burst observations
  21. GRB050813: SWIFT/UVOT observation
  22. GRB 050813: Swift XRT afterglow localization
  23. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  24. Detection of an intermediate burst from SGR 1806-20 on August 8
  25. GRB050805b: CrAO optical limit
  26. GRB050803, optical observations
  27. Retraction of Swift Trigger 149131 (GRB 050805B)
  28. GRB 050805b: OHP optical limits
  29. GRB 050805b: TAROT optical limits
  30. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  31. Swift-BAT trigger 149118 is probably not a GRB
  32. GRB050802: TNG optical observations
  33. GRB050803: Radio Observation
  34. GRB 050803: RTT150 optical observations
  35. GRB050801: Radio Observation
  36. GRB050730: Radio Detection
  37. GRB 050803: Keck Observations
  38. GRB 050802.422: Fading of the afterglow and detection of the host
  39. GRB 050803: TAROT optical limits
  40. GRB050802 radio non-detection
  41. GRB 050730: OHP optical observations
  42. GRB050801: Optical photometry and decay index
  43. GRB 050802: XRT position
  44. GRB 050802: Swift Gamma-ray Burst
  45. GCN 050801: early Swift XRT analysis results
  46. GRB 050730: early TAROT optical observations
  47. GRB 050730, spectra and optical photometry
  48. GRB 050730 XMM-Newton observation
  49. GRB050730: Swift-BAT detection of a weak burst
  50. GRB050713: analysis of the XMM-Newton observation
  51. GRB050709: Second Epoch Chandra Observation
  52. GRB 050724: Optical Variability in Nearby Galaxy
  53. GRB 050724: J-band observations
  54. GRB 050724: GMOS Imaging and Spectroscopy
  55. GRB050724: Radio Observation
  56. GRB 050724: Swift/UVOT Upper Limit
  57. GRB 050724: possible host galaxy in DSS
  58. GRB050721A: optical decay
  59. GRB 050721: optical afterglow confirmed
  60. GRB 050709: Refined Spectral and Temporal Properties
  61. GRB050714b: Radio Observation
  62. GRB050712: Radio Observations
  63. GRB050713a: Radio Observation
  64. GRB 050712, Tautenburg optical afterglow observations
  65. Swift-BAT detection of a possible GRB
  66. GRB 050714B: VLT R-band observations
  67. GRB 050717: Additional LCO observations
  68. GRB 050716; J-band observations
  69. GRB 050717: LCO near-IR observations
  70. Swift/UVOT Observations of GRB 050717
  71. GRB 050717: Swift-BAT refined analysis
  72. GRB050712: optical limits
  73. GRB050717: Swift XRT position
  74. Swift detection of GRB 050717
  75. Swift UVOT Observations of GRB 050716
  76. GRB 050716: Lulin B and R band optical observations
  77. GRB050716, optical observation
  78. GRB050716: Faulkes North Telescope observation
  79. GRB 050713b: RTT150 optical observations
  80. GRB 050714B: optical afterglow
  81. GRB 050714, R-band candidate
  82. GRB 050714, optical observations
  83. GRB 050713A: RAPTOR detection of early optical emission
  84. GRB050713B :Swift/UVOT observations
  85. GRB050712: TNG R-band observations
  86. GRB 050713A: Swift/UVOT observation
  87. GRB050712: Swift UVOT Observation of Afterglow Emission
  88. GRB 050713A XMM-Newton observation
  89. GRB050713B: Faulkes North Telescope observation
  90. GRB050709 : Chandra source optical counterpart
  91. GRB 050712, optical observations
  92. GRB050709: Candidate X-ray Afterglow from Chandra
  93. GRB050713: possible I-band afterglow
  94. GRB050709: Radio Observations
  95. GRB050712: UVOT candidate optical counterpart
  96. GRB 050709: LCO40 Observations
  97. PROMPT Rc Observations of GRB 050709
  98. GRB 050525a: PROMPT VRcIc Detections
  99. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  100. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration

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