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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"

37528 results found.

  1. GRB 050716; J-band observations
  2. Konus-Wind observation of GRB 050717
  3. GRB 050717: LCO near-IR observations
  4. Swift/UVOT Observations of GRB 050717
  5. GRB 050717: Swift-BAT refined analysis
  6. GRB 050717: Refined XRT analysis.
  7. GRB050712: optical limits
  8. Swift detection of GRB 050717
  9. GRB 050716 - UKIRT identification of candidate afterglow
  10. Swift UVOT Observations of GRB 050716
  11. GRB 050716: Refined XRT analysis.
  12. GRB 050716: Lulin B and R band optical observations
  13. GRB050716, optical observation
  14. GRB 050716: Optical Observations
  15. GRB050716: Faulkes North Telescope observation
  16. Swift/BAT detection of GRB 050716
  17. GRB 050715: Swift-BAT detection
  18. Swift UVOT Observations of GRB 050714B
  19. Konus-Wind observation of GRB 050713A
  20. GRB 050714B: refined XRT analysis
  21. GRB 050713b: RTT150 optical observations
  22. GRB 050714B: candidate afterglow does not fade
  23. GRB050714B: Refined analysis of the Swift-BAT burst
  24. GRB 050714B: optical afterglow
  25. Swift detection of a long transient (GRB 050714B?)
  26. GRB 050709: optical afterglow candidate
  27. GRB 050714, R-band candidate
  28. GRB 050714: Swift XRT afterglow position
  29. GRB 050714, optical observations
  30. GRB 050714A: ROTSE-III Optical Limits
  31. GRB 050714 - A long GRB detected with INTEGRAL
  32. GRB 050713A: XRT refined analysis
  33. GRB 050709: Spectroscopy
  34. GRB 050713A: RAPTOR detection of early optical emission
  35. GRB050713B :Swift/UVOT observations
  36. GRB050712: TNG R-band observations
  37. GRB 050713B: Swift-BAT Refined Analysis
  38. Swift-BAT Trigger 145729 is not a GRB
  39. GRB 050713A: Swift/UVOT observation
  40. GRB 050713A : Swift-BAT Refined Analysis
  41. GRB 050713A : Lulin R-band observation
  42. GRB 050713A XMM-Newton observation
  43. GRB 050713b : Lulin R-band observations
  44. GRB050713B: Faulkes North Telescope observation
  45. RBO RI observations of GRB 050713A
  46. GRB 050713B
  47. GRB050709 : Chandra source optical counterpart
  48. GRB050713: Liverpool Telescope prompt observations
  49. GRB 050712, optical observations
  50. GRB 050713 : Planned XMM-Newton observation
  51. GRB050709: Candidate X-ray Afterglow from Chandra
  52. GRB 050713, R-band observations at NOT
  53. GRB 050713: ARC NIR Detections and Identification of Fading
  54. GRB050713: possible I-band afterglow
  55. GRB 050713: Swift detection of Bright Burst
  56. GRB 050713A: ROTSE-III Optical Limits
  57. GRB 050709: Swift UVOT and XRT observations
  58. GRB 050712: Swift-BAT Refined Analysis
  59. GRB 050712: Swift XRT afterglow position
  60. GRB 050712: Swift detection of a weak burst
  61. GRB 050709: LCO40 Observations
  62. GRB050709: A Possible Short-Hard GRB Localized by HETE
  63. PROMPT Rc Observations of GRB 050709
  64. GRB 050525a: PROMPT VRcIc Detections
  65. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  66. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  67. GRB 050626 optical observations
  68. GRB 050626: Swift XRT observations
  69. GRB 050701
  70. GRB 050701, optical observations
  71. GRB 050408: ARC 3.5-meter NIR Observations
  72. GRB 050701: Refined XRT analysis
  73. Swift UVOT observations of GRB 050701
  74. GRB 050701: Swift XRT afterglow position
  75. Swift trigger 143708 is really GRB 050701
  76. GRB 050607, radio observations
  77. GRB 050626 - Correction to GCN 3552
  78. GRB 050626 - a long GRB detected with INTEGRAL
  79. GRB 050525A: Swift Late-Time Decay Rate
  80. H3804: A Possible New XRB Detected by HETE
  81. XRF 050509c: Optical monitoring
  82. IBAS Alert #2512 is NOT a GRB
  83. GRB 050416(a): Host Galaxy Redshift Determination
  84. GRB 050607: MDM Observation
  85. GRB 050607 optical decay
  86. GRB 050607: RTT150 optical observations
  87. GRB 050607 : Lulin R-band observation
  88. GRB 050607: PROMPT VRcIc Observations
  89. GRB 050607: RAPTOR-S Early Optical Limits
  90. GRB 050525a, Mid-Infrared Observations
  91. GRB 050607: Optical decay and spectral slope
  92. GRB 050607: MDM Observations
  93. GRB050607,optical observation
  94. GRB 050607 - XRT refined data analysis
  95. Optical Afterglow of GRB 050607
  96. GRB050607 optical limit by "Pi of the Sky"
  97. GRB050607: Swift Detection of a long GRB
  98. GRB050607: P60 Observations
  99. GRB 050603: prediction of t_break
  100. Limits on a SN in the field of GRB 050509b

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