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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"

19858 results found.

  1. GRB 050820B: Swift XRT position
  2. GRB050820: refined XRT analysis
  3. GRB050819: refined XRT analysis
  4. GRB 050820: Swift detection of a GRB
  5. GRB 050819 Swift-BAT refined analysis
  6. GRB050819: Swift-BAT detection of a weak burst
  7. Swift Trigger 150823 is HETE J1900.1-2455
  8. GRB 050817: Optical observations
  9. GRB050817: Swift-BAT Detection of a burst
  10. GRB 050814: continued fading
  11. GRB050815: Refined analysis of the Swift-BAT burst
  12. GRB 050815: ROTSE-III Optical Limits
  13. GRB050815: Swift-BAT detection of a burst
  14. GRB050814: Fading red source
  15. GRB050814: P60 Optical Afterglow Candidate
  16. GRB 050813: Non-fading of afterglow candidate
  17. GRB 050814: XRT refined analysis
  18. GRB050814: SWIFT/UVOT observation
  19. GRB 050814: Swift XRT Afterglow Localization
  20. GRB 050814: Swift detection of a burst
  21. GRB 050813: Magellan detection of a high redshift galaxy cluster
  22. GRB050813, SDSS pre-burst observations
  23. GRB050813: SWIFT/UVOT observation
  24. GRB 050813: Swift XRT afterglow localization
  25. GRB050803: CrAO optical observations, no OT candidate
  26. GRB050805b: CrAO optical limit
  27. GRB050803, optical observations
  28. Retraction of Swift Trigger 149131 (GRB 050805B)
  29. GRB 050805b: OHP optical limits
  30. GRB 050805b: TAROT optical limits
  31. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  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. GRB050803: Swift-BAT detection of a very long burst
  41. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  42. GRB 050802: Swift/UVOT optical and UV detections
  43. GRB050802 radio non-detection
  44. GRB 050730: OHP optical observations
  45. GRB050801: Optical photometry and decay index
  46. GRB 050802: Swift Gamma-ray Burst
  47. GCN 050801: early Swift XRT analysis results
  48. GRB 050730, corrected photometry and break?
  49. GRB 050730: early TAROT optical observations
  50. GRB 050730, spectra and optical photometry
  51. GRB 050730 XMM-Newton observation
  52. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  53. GRB050730: Swift-BAT detection of a weak burst
  54. GRB 050713A: Swift XRT extended light curve
  55. GRB 050724: WHT optical observations
  56. GRB050713: analysis of the XMM-Newton observation
  57. GRB050709: Second Epoch Chandra Observation
  58. GRB050709: Second Epoch Chandra Observation
  59. GRB 050724: Optical Variability in Nearby Galaxy
  60. GRB 050724: J-band observations
  61. GRB 050724: GMOS Imaging and Spectroscopy
  62. GRB050724: Radio Observation
  63. GRB 050724: Swift/UVOT Upper Limit
  64. GRB 050724: possible host galaxy in DSS
  65. GRB050721A: optical decay
  66. GRB 050721: optical afterglow confirmed
  67. GRB050714b: Radio Observation
  68. GRB050712: Radio Observations
  69. GRB050713a: Radio Observation
  70. GRB 050712, Tautenburg optical afterglow observations
  71. Swift-BAT detection of a possible GRB
  72. GRB 050714B: VLT R-band observations
  73. GRB 050717: Additional LCO observations
  74. GRB 050716; J-band observations
  75. GRB 050717: LCO near-IR observations
  76. Swift/UVOT Observations of GRB 050717
  77. GRB050717: Swift XRT position
  78. Swift detection of GRB 050717
  79. Swift UVOT Observations of GRB 050716
  80. GRB 050716: Lulin B and R band optical observations
  81. GRB050716, optical observation
  82. GRB050716: Faulkes North Telescope observation
  83. Swift/BAT detection of GRB 050716
  84. Konus-Wind observation of GRB 050713A
  85. GRB 050713b: RTT150 optical observations
  86. GRB 050714B: optical afterglow
  87. GRB 050714, R-band candidate
  88. GRB 050714, optical observations
  89. GRB 050713A: RAPTOR detection of early optical emission
  90. GRB050713B :Swift/UVOT observations
  91. GRB050712: TNG R-band observations
  92. GRB 050713A: Swift/UVOT observation
  93. GRB050712: Swift UVOT Observation of Afterglow Emission
  94. GRB 050713A XMM-Newton observation
  95. GRB050713B: Faulkes North Telescope observation
  96. RBO RI observations of GRB 050713A
  97. GRB050709 : Chandra source optical counterpart
  98. GRB050713: Liverpool Telescope prompt observations
  99. GRB 050712, optical observations
  100. GRB050709: Candidate X-ray Afterglow from Chandra

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