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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"

20357 results found.

  1. GRB050820: refined XRT analysis
  2. GRB050819: refined XRT analysis
  3. GRB 050820: Swift detection of a GRB
  4. GRB 050819 Swift-BAT refined analysis
  5. GRB050819: Swift-BAT detection of a weak burst
  6. Swift Trigger 150823 is HETE J1900.1-2455
  7. GRB 050817: Optical observations
  8. GRB050817: Swift-BAT Detection of a burst
  9. GRB 050814: continued fading
  10. GRB050815: Refined analysis of the Swift-BAT burst
  11. GRB 050815: ROTSE-III Optical Limits
  12. GRB050815: Swift-BAT detection of a burst
  13. GRB050814: Fading red source
  14. GRB050814: P60 Optical Afterglow Candidate
  15. GRB 050813: Non-fading of afterglow candidate
  16. GRB 050814: XRT refined analysis
  17. GRB050814: SWIFT/UVOT observation
  18. GRB 050814: Swift XRT Afterglow Localization
  19. GRB 050814: Swift detection of a burst
  20. GRB 050813: Magellan detection of a high redshift galaxy cluster
  21. GRB050813, SDSS pre-burst observations
  22. GRB050813: SWIFT/UVOT observation
  23. GRB 050813: Swift XRT afterglow localization
  24. GRB050803: CrAO optical observations, no OT candidate
  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. GRB050802: TNG optical observations
  32. GRB050803: Radio Observation
  33. GRB 050803: RTT150 optical observations
  34. GRB050801: Radio Observation
  35. GRB050730: Radio Detection
  36. GRB 050803: Keck Observations
  37. GRB 050802.422: Fading of the afterglow and detection of the host
  38. GRB 050803: TAROT optical limits
  39. GRB050803: Swift-BAT detection of a very long burst
  40. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  41. GRB 050802: Swift/UVOT optical and UV detections
  42. GRB050802 radio non-detection
  43. GRB 050730: OHP optical observations
  44. GRB050801: Optical photometry and decay index
  45. GRB 050802: Swift Gamma-ray Burst
  46. GCN 050801: early Swift XRT analysis results
  47. GRB 050730, corrected photometry and break?
  48. GRB 050730: early TAROT optical observations
  49. GRB 050730, spectra and optical photometry
  50. GRB 050730 XMM-Newton observation
  51. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  52. GRB050730: Swift-BAT detection of a weak burst
  53. GRB 050713A: Swift XRT extended light curve
  54. GRB 050724: WHT optical observations
  55. GRB050713: analysis of the XMM-Newton observation
  56. GRB050709: Second Epoch Chandra Observation
  57. GRB050709: Second Epoch Chandra Observation
  58. GRB 050724: Optical Variability in Nearby Galaxy
  59. GRB 050724: J-band observations
  60. GRB 050724: GMOS Imaging and Spectroscopy
  61. GRB050724: Radio Observation
  62. GRB 050724: Swift/UVOT Upper Limit
  63. GRB 050724: possible host galaxy in DSS
  64. GRB050721A: optical decay
  65. GRB 050721: optical afterglow confirmed
  66. GRB050714b: Radio Observation
  67. GRB050712: Radio Observations
  68. GRB050713a: Radio Observation
  69. GRB 050712, Tautenburg optical afterglow observations
  70. Swift-BAT detection of a possible GRB
  71. GRB 050714B: VLT R-band observations
  72. GRB 050717: Additional LCO observations
  73. GRB 050716; J-band observations
  74. GRB 050717: LCO near-IR observations
  75. Swift/UVOT Observations of GRB 050717
  76. GRB050717: Swift XRT position
  77. Swift detection of GRB 050717
  78. Swift UVOT Observations of GRB 050716
  79. GRB 050716: Lulin B and R band optical observations
  80. GRB050716, optical observation
  81. GRB050716: Faulkes North Telescope observation
  82. Swift/BAT detection of GRB 050716
  83. Konus-Wind observation of GRB 050713A
  84. GRB 050713b: RTT150 optical observations
  85. GRB 050714B: optical afterglow
  86. GRB 050714, R-band candidate
  87. GRB 050714, optical observations
  88. GRB 050713A: RAPTOR detection of early optical emission
  89. GRB050713B :Swift/UVOT observations
  90. GRB050712: TNG R-band observations
  91. GRB 050713A: Swift/UVOT observation
  92. GRB050712: Swift UVOT Observation of Afterglow Emission
  93. GRB 050713A XMM-Newton observation
  94. GRB050713B: Faulkes North Telescope observation
  95. RBO RI observations of GRB 050713A
  96. GRB050709 : Chandra source optical counterpart
  97. GRB050713: Liverpool Telescope prompt observations
  98. GRB 050712, optical observations
  99. GRB050709: Candidate X-ray Afterglow from Chandra
  100. GRB050713: possible I-band afterglow

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