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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"

28068 results found.

  1. GRB 050709: optical afterglow candidate
  2. GRB 050714: Swift XRT afterglow position
  3. GRB 050713A: XRT refined analysis
  4. GRB 050709: Spectroscopy
  5. GRB 050713A: RAPTOR detection of early optical emission
  6. GRB050713B :Swift/UVOT observations
  7. GRB050713b: XRT refined analysis
  8. GRB050712: TNG R-band observations
  9. GRB 050713A: Swift/UVOT observation
  10. GRB050712: Swift UVOT Observation of Afterglow Emission
  11. GRB 050713A : Lulin R-band observation
  12. GRB 050713A XMM-Newton observation
  13. GRB050713B: Faulkes North Telescope observation
  14. RBO RI observations of GRB 050713A
  15. GRB 050713B
  16. GRB050713: Liverpool Telescope prompt observations
  17. GRB050709: Candidate X-ray Afterglow from Chandra
  18. GRB 050713, R-band observations at NOT
  19. GRB050713: possible I-band afterglow
  20. GRB 050713: Swift detection of Bright Burst
  21. GRB 050713A: ROTSE-III Optical Limits
  22. GRB050712: XRT refined analysis
  23. GRB 050709: Swift UVOT and XRT observations
  24. GRB050712: UVOT candidate optical counterpart
  25. GRB 050712: Swift XRT afterglow position
  26. GRB 050712: Swift detection of a weak burst
  27. GRB050709: A Possible Short-Hard GRB Localized by HETE
  28. GRB 050525a: PROMPT VRcIc Detections
  29. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  30. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  31. GRB 050626 optical observations
  32. GRB 050626: Swift XRT observations
  33. GRB 050701
  34. GRB 050701, optical observations
  35. GRB 050408: ARC 3.5-meter NIR Observations
  36. GRB 050701: Refined XRT analysis
  37. Swift UVOT observations of GRB 050701
  38. GRB 050701: Swift XRT afterglow position
  39. Swift trigger 143708 is really GRB 050701
  40. GRB 050607, radio observations
  41. GRB 050525A: Swift Late-Time Decay Rate
  42. GRB050525a: HST Observations
  43. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  44. XRF 050509c: Optical monitoring
  45. XRF050509c: Radio Detection
  46. GRB 050416(a): Host Galaxy Redshift Determination
  47. GRB 050607: MDM Observation
  48. GRB 050607 optical decay
  49. GRB050607: refined analysis of prompt REM observations
  50. Swift/UVOT observations of GRB050607
  51. GRB 050607 : Lulin R-band observation
  52. GRB 050607: PROMPT VRcIc Observations
  53. GRB 050607: RAPTOR-S Early Optical Limits
  54. GRB050607: KAIT optical limits
  55. GRB 050525a, Mid-Infrared Observations
  56. GRB 050607: Optical decay and spectral slope
  57. GRB 050607: MDM Observations
  58. GRB 050607 - XRT refined data analysis
  59. Optical Afterglow of GRB 050607
  60. GRB050607: Swift Detection of a long GRB
  61. Limits on a SN in the field of GRB 050509b
  62. GRB 050603: Redshift
  63. GRB 050603 - XRT data analysis of the first day
  64. GRB 050603: Analysis of UVOT data
  65. GRB050603: Fading Afterglow observed by Swift UVOT
  66. GRB050603, submillimetre observations
  67. GRB 050603: Swift XRT Position
  68. GRB050603: Radio Detection
  69. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  70. GRB 050603: Afterglow Identification from LCO
  71. Swift/BAT Detection of GRB050603
  72. GRB 050408: jet break in the XRT light curve
  73. GRB 050525a, infrared observations
  74. GRB 050525a, SMARTS optical/IR afterglow observations
  75. GRB050528, XRT observations
  76. Possible GRB050528: no candidate from Liverpool Telescope
  77. Swift-BAT detection of possible GRB 050528
  78. GRB 050509b: refined XRT/Chandra afterglow position analysis
  79. GRB 050525a: SARA Observations
  80. GRB 050525: MITSuME Optical Observation in VRI
  81. GRB 050525a: MDM Observations
  82. GRB 050525 : Lulin optical afterglow observations
  83. GRB050525: Super-LOTIS observations
  84. GRB050306: optical afterglow not confirmed
  85. GRB 050525: BART optical observation
  86. GRB050525: Optical observations
  87. GRB 050525: TAROT observations of the early afterglow
  88. INTEGRAL detection of GRB 050525
  89. GRB 050525, infrared observations
  90. GRB 050525: Optical observation
  91. GRB 050525: observatons of the optical afterglow
  92. GRB050525: ROTSE-III Refined Analysis
  93. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  94. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  95. XRF050522: NIR observations of XRT candidate
  96. XRF 050522: Swift XRT refined analysis
  97. GRB 050509A: Further I-band imaging
  98. RBO Observations of GRB050522
  99. GRB050509b: optical observations
  100. GRB050520: Radio Observations

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