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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"

24378 results found.

  1. GRB 050505: Keck I-band Magnitude
  2. GRB 050505: early time observations
  3. GRB 050505, simultaneous optical observation
  4. GRB050505: Infrared observations
  5. GRB 050505: Further Swift UVOT observations.
  6. GRB050505: AAVSO observations
  7. GRB 050416b:Swift XRT afterglow upper limits
  8. GRB 050416b:Swift XRT afterglow upper limits
  9. Swift UVOT observation of GRB 050504
  10. GRB 050504, R band Observations
  11. GRB 050504: A long GRB detected with INTEGRAL
  12. GRB (?) 050504: IR Observations, Intriguing Source
  13. Renewal of SGR 1806-20 activity
  14. GRB 050502a: RBO Observations
  15. GRB050502B Swift-BAT refined analysis
  16. Swift UVOT refined analysis
  17. GRB050502B: Optical Limits from ANU 1m
  18. Swift Detection of the Bright Burst GRB050502b
  19. GRB 050502: INTEGRAL results
  20. GRB 050502 - A long GRB detected with INTEGRAL
  21. GRB 050502: ROTSE-III Detection of Possible Counterpart
  22. Swift-BAT Trigger 115881 is not a real GRB
  23. Swift/BAT possible detection of a weak burst GRB050430
  24. GRB 050422: Swift-UVOT observation
  25. GRB 050422: Swift-BAT refined analysis
  26. Swift Detection of GRB 050422
  27. GRB 050421: Swift-UVOT observation
  28. GRB 050421: IR Observations
  29. GRB 050421: Swift-BAT refined analysis
  30. GRB 050421: ROTSE-III Optical Limits
  31. GRB 050421: NIR observations
  32. GRB 050416b: Tentative Swift XRT Position
  33. GRB 050315: potential host galaxy
  34. GRB050326: analysis of the XMM-Newton observation
  35. GRB050418: Null Optical Observations
  36. GRB 050412: Chandra observations
  37. GRB 050418: Swift-BAT refined analysis
  38. GRB 050416b: Swift-BAT refined analysis
  39. GRB 050416: Swift/UVOT refined analysis
  40. IBAS GRB Alert # 2463: not a GRB
  41. GRB050416: Maidanak optical observations
  42. GRB 050416,optical observation
  43. Swift BAT/XRT Detection of GRB 050416
  44. GRB050408: optical observation
  45. GRB 050412: PROMPT VRcIc Observations
  46. GRB 050412: Swift-BAT refined analysis
  47. GRB 050412: LCO Optical Observations
  48. GRB050412: P60 Observations
  49. GRB 050410, optical observations
  50. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  51. GRB 050410 R band Optical Observations
  52. GRB050410 : Null detection report
  53. GRB 050408: Swift XRT measurement of possible jet break
  54. GRB050410: MASTER optical observations
  55. GRB 050410: Early observations with Swift-UVOT
  56. Swift-BAT detection of GRB 050410
  57. GRB 050408: WIDGET simultaneous optical observations
  58. GRB 050408: Properties of the Host Galaxy
  59. GRB 050408: Swift XRT analysis
  60. GRB 050408, optical observations
  61. GRB050408: REM NIR and Optical observation
  62. GRB 050408,optical observation
  63. GRB 050408 Optical Observations
  64. GRB 050408: Mercator Optical Observations
  65. GRB 050408: ROTSE-III Optical Limits
  66. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  67. GRB050408: MASTER optical observations
  68. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  69. GRB 050406: early Swift XRT analysis results
  70. GRB 050406 BAT refined analysis
  71. GRB 050406: Early observations with Swift-UVOT
  72. GRB050401: Radio observation at 610 MHz with GMRT
  73. GRB050401: Maidanak optical observation
  74. GRB 050401 BAT refined analysis
  75. GRB050401: TNG R-band observation
  76. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  77. Swift-BAT detection of GRB 050401
  78. GRB050331: No Afterglow Detected
  79. GRB 050331: Swift UVOT Source
  80. Konus-Wind observation of GRB 050326
  81. GRB050326: optical limit
  82. GRB 050326: Early observations with Swift-UVOT
  83. GRB 050326 BAT refined analysis
  84. Swift-BAT detection of a bright GRB 050326
  85. GRB050319: optical observation, March 20-22
  86. Swift-BAT trigger 112060 is not a real GRB
  87. GRB 050319: ROTSE-III Refined Analysis
  88. GRB 050318: Swift-BAT refined analysis
  89. GRB 050319: Swift-UVOT detection of the afterglow
  90. GRB 050315: Variability Analysis of Swift BAT Time History
  91. GRB050319: BR optical photometry
  92. GRB 050318: SWIFT-UVOT refined analysis
  93. GRB 050319 : Confirmation of optical afterglow decay
  94. GRB 050319: Swift-BAT refined analysis
  95. GRB050319,optical observation
  96. Swift Detection of GRB 050319
  97. GRB 050318: Swift/UVOT detection of afterglow emission
  98. Swift-BAT detection of GRB 050318
  99. GRB 050315, SMARTS optical afterglow decay
  100. GRB050223: analysis of the XMM-Newton observation

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