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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"

28038 results found.

  1. Swift-BAT detection of a possible GRB
  2. GRB 050714B: VLT R-band observations
  3. GRB 050717: Additional LCO observations
  4. GRB 050716; J-band observations
  5. GRB 050717: LCO near-IR observations
  6. Swift/UVOT Observations of GRB 050717
  7. GRB 050717: Swift-BAT refined analysis
  8. GRB050717: Swift XRT position
  9. Swift detection of GRB 050717
  10. Swift UVOT Observations of GRB 050716
  11. GRB 050716: Refined XRT analysis.
  12. GRB050716: Refined analysis of the Swift-BAT burst
  13. GRB 050716: Lulin B and R band optical observations
  14. GRB050716, optical observation
  15. GRB050716: Faulkes North Telescope observation
  16. GRB050715: Refined analysis of the Swift-BAT burst
  17. GRB 050715: Swift-BAT detection
  18. GRB 050713b: RTT150 optical observations
  19. GRB050714B: Refined analysis of the Swift-BAT burst
  20. GRB 050714B: optical afterglow
  21. GRB 050714, R-band candidate
  22. GRB 050714, optical observations
  23. GRB 050713A: XRT refined analysis
  24. GRB 050713A: RAPTOR detection of early optical emission
  25. GRB050713B :Swift/UVOT observations
  26. GRB050713b: XRT refined analysis
  27. GRB050712: TNG R-band observations
  28. GRB 050713B: Swift-BAT Refined Analysis
  29. GRB 050713A: Swift/UVOT observation
  30. GRB 050713A : Swift-BAT Refined Analysis
  31. GRB050712: Swift UVOT Observation of Afterglow Emission
  32. GRB 050713A : Lulin R-band observation
  33. GRB 050713A XMM-Newton observation
  34. GRB 050713b : Lulin R-band observations
  35. GRB050713B: Faulkes North Telescope observation
  36. RBO RI observations of GRB 050713A
  37. GRB 050713B
  38. GRB050709 : Chandra source optical counterpart
  39. GRB050713: Liverpool Telescope prompt observations
  40. GRB 050712, optical observations
  41. GRB050709: Candidate X-ray Afterglow from Chandra
  42. GRB050713: possible I-band afterglow
  43. GRB050712: XRT refined analysis
  44. GRB050709: Radio Observations
  45. GRB 050709: Swift UVOT and XRT observations
  46. GRB 050712: Swift-BAT Refined Analysis
  47. GRB050712: UVOT candidate optical counterpart
  48. GRB 050709: LCO40 Observations
  49. GRB050709, optical observations
  50. PROMPT Rc Observations of GRB 050709
  51. GRB 050525a: PROMPT VRcIc Detections
  52. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  53. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  54. GRB 050626: Swift XRT observations
  55. GRB 050408: ARC 3.5-meter NIR Observations
  56. GRB 050701: Refined XRT analysis
  57. Swift UVOT observations of GRB 050701
  58. GRB050701: Swift-BAT Refined analysis
  59. Swift trigger 143708 is really GRB 050701
  60. GRB 050607, radio observations
  61. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  62. GRB050525a: HST Observations
  63. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  64. XRF 050509c: Optical monitoring
  65. Konus-Wind observation of an intermediate burst from SGR 1806-20
  66. XRF050509c: Radio Detection
  67. GRB 050607 optical decay
  68. GRB050607: refined analysis of prompt REM observations
  69. GRB 050607: PROMPT VRcIc Observations
  70. GRB 050607: Optical decay and spectral slope
  71. GRB050607,optical observation
  72. Optical Afterglow of GRB 050607
  73. GRB050607: Swift Detection of a long GRB
  74. GRB050607: prompt REM observations
  75. Limits on a SN in the field of GRB 050509b
  76. GRB 050603 - XRT data analysis of the first day
  77. GRB050603, submillimetre observations
  78. GRB050603: Radio Detection
  79. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  80. GRB 050603: INTEGRAL shows it is not a short GRB
  81. GRB 050525a, infrared observations
  82. GRB050528, XRT observations
  83. GRB050528: updated Liverpool Telescope limits
  84. Swift-BAT GRB 050528: a soft burst
  85. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  86. Possible GRB050528: no candidate from Liverpool Telescope
  87. GRB050525a: Radio Observations
  88. GRB 050509b: refined XRT/Chandra afterglow position analysis
  89. GRB 050525: RTT150, Optical observations
  90. GRB 050525a: SARA Observations
  91. GRB 050525B: Swift-BAT observations
  92. GRB 050525: MITSuME Optical Observation in VRI
  93. GRB050525A,optical observation
  94. GRB050525: Super-LOTIS observations
  95. GRB 050525, spectral lag pseudo-redshift
  96. GRB050306: optical afterglow not confirmed
  97. GRB 050525: BART optical observation
  98. GRB 050525A: BOOTES simultaneous optical observations
  99. GRB 050525A: Swift-BAT refined analysis
  100. GRB050525: Optical observations

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