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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"

26352 results found.

  1. GRB050724: Radio Observation
  2. GRB 050724: Optical imaging/astrometry
  3. GRB 050724: Swift/UVOT Upper Limit
  4. GRB050724: Refined analysis of the Swift-BAT possible short burst
  5. GRB 050724: possible host galaxy in DSS
  6. GRB 050721A: Swift-BAT refined analysis
  7. GRB 050721A: Early Swift XRT analysis results
  8. GRB050721A: optical decay
  9. GRB 050721: optical afterglow confirmed
  10. GRB 050709: Refined Spectral and Temporal Properties
  11. GRB050714b: Radio Observation
  12. GRB050712: Radio Observations
  13. GRB050713a: Radio Observation
  14. GRB 050712, Tautenburg optical afterglow observations
  15. Swift-BAT detection of a possible GRB
  16. GRB 050714B: VLT R-band observations
  17. GRB 050717: Additional LCO observations
  18. GRB 050716; J-band observations
  19. GRB 050717: LCO near-IR observations
  20. Swift/UVOT Observations of GRB 050717
  21. GRB 050717: Swift-BAT refined analysis
  22. GRB050717: Swift XRT position
  23. Swift detection of GRB 050717
  24. Swift UVOT Observations of GRB 050716
  25. GRB 050716: Refined XRT analysis.
  26. GRB050716: Refined analysis of the Swift-BAT burst
  27. GRB 050716: Lulin B and R band optical observations
  28. GRB050716, optical observation
  29. GRB050716: Faulkes North Telescope observation
  30. GRB050715: Refined analysis of the Swift-BAT burst
  31. GRB 050715: Swift-BAT detection
  32. GRB 050713b: RTT150 optical observations
  33. GRB050714B: Refined analysis of the Swift-BAT burst
  34. GRB 050714B: optical afterglow
  35. GRB 050714, R-band candidate
  36. GRB 050714, optical observations
  37. GRB 050713A: XRT refined analysis
  38. GRB 050713A: RAPTOR detection of early optical emission
  39. GRB050713B :Swift/UVOT observations
  40. GRB050713b: XRT refined analysis
  41. GRB050712: TNG R-band observations
  42. GRB 050713B: Swift-BAT Refined Analysis
  43. GRB 050713A: Swift/UVOT observation
  44. GRB 050713A : Swift-BAT Refined Analysis
  45. GRB050712: Swift UVOT Observation of Afterglow Emission
  46. GRB 050713A : Lulin R-band observation
  47. GRB 050713A XMM-Newton observation
  48. GRB 050713b : Lulin R-band observations
  49. GRB050713B: Faulkes North Telescope observation
  50. RBO RI observations of GRB 050713A
  51. GRB 050713B
  52. GRB050709 : Chandra source optical counterpart
  53. GRB050713: Liverpool Telescope prompt observations
  54. GRB 050712, optical observations
  55. GRB050709: Candidate X-ray Afterglow from Chandra
  56. GRB050713: possible I-band afterglow
  57. GRB050712: XRT refined analysis
  58. GRB050709: Radio Observations
  59. GRB 050709: Swift UVOT and XRT observations
  60. GRB 050712: Swift-BAT Refined Analysis
  61. GRB050712: UVOT candidate optical counterpart
  62. GRB 050709: LCO40 Observations
  63. GRB050709, optical observations
  64. PROMPT Rc Observations of GRB 050709
  65. GRB 050525a: PROMPT VRcIc Detections
  66. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  67. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  68. GRB 050626: Swift XRT observations
  69. GRB 050408: ARC 3.5-meter NIR Observations
  70. GRB 050701: Refined XRT analysis
  71. Swift UVOT observations of GRB 050701
  72. GRB050701: Swift-BAT Refined analysis
  73. Swift trigger 143708 is really GRB 050701
  74. GRB 050607, radio observations
  75. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  76. GRB050525a: HST Observations
  77. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  78. XRF 050509c: Optical monitoring
  79. Konus-Wind observation of an intermediate burst from SGR 1806-20
  80. XRF050509c: Radio Detection
  81. GRB 050607 optical decay
  82. GRB050607: refined analysis of prompt REM observations
  83. GRB 050607: PROMPT VRcIc Observations
  84. GRB 050607: Optical decay and spectral slope
  85. GRB050607,optical observation
  86. Optical Afterglow of GRB 050607
  87. GRB050607: Swift Detection of a long GRB
  88. GRB050607: prompt REM observations
  89. Limits on a SN in the field of GRB 050509b
  90. GRB 050603 - XRT data analysis of the first day
  91. GRB050603, submillimetre observations
  92. GRB050603: Radio Detection
  93. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  94. GRB 050603: INTEGRAL shows it is not a short GRB
  95. GRB 050525a, infrared observations
  96. GRB050528, XRT observations
  97. GRB050528: updated Liverpool Telescope limits
  98. Swift-BAT GRB 050528: a soft burst
  99. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  100. Possible GRB050528: no candidate from Liverpool Telescope

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