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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"

26316 results found.

  1. GRB 050408: SDSS Field Calibration
  2. GRB050412: P60 Observations
  3. GRB 050412: Swift XRT Position
  4. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  5. GRB 050412: IR and Optical observations
  6. GRB 050412: IR Observations
  7. GRB050408: Radio Observations
  8. GRB 050401: Optical limit
  9. GRB050410: P60 Observations
  10. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  11. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  12. GRB050410: Radio Observations
  13. GRB050410: MASTER optical observations
  14. GRB 050410: Early observations with Swift-UVOT
  15. Swift-BAT detection of GRB 050410
  16. GRB 050408: Inconsistency of host galaxy identification
  17. GRB 050408: Subaru Observations
  18. GRB 050408: WIDGET simultaneous optical observations
  19. GRB 050408: Properties of the Host Galaxy
  20. GRB050408: Radio Observations
  21. GRB 050408: Swift XRT analysis
  22. GRB 050408: Optical limit at 20 min after the burst
  23. GRB050408: REM NIR and Optical observation
  24. GRB 050408,optical observation
  25. GRB 050408: Mercator Optical Observations
  26. GRB 050408: Optical afterglow confirmed
  27. GRB 050408: opitcal observation
  28. GRB 050408, optical observations
  29. GRB 050408 optical candidate
  30. GRB 050408: Swift XRT Position
  31. GRB050408: MASTER optical observations
  32. GRB050401: Radio Detection
  33. GRB 050406: early Swift XRT analysis results
  34. GRB 050406 BAT refined analysis
  35. GRB 050406: Early observations with Swift-UVOT
  36. Swift-BAT detection of GRB 050406
  37. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  38. GRB 050401: VLT spectroscopic redshift
  39. GRB 050401 BAT refined analysis
  40. GRB050401: TNG R-band observation
  41. GRB 050402: Early observations with Swift-UVOT
  42. Swift Trigger 113225: P60 Observations
  43. GRB 050401: Optical afterglow confirmed
  44. GRB 050401: Prompt XRT position
  45. Retraction of three Swift GRB triggers
  46. GRB050331: No Afterglow Detected
  47. Swift-BAT detection of GRB 050331b
  48. GRB 050331: Swift UVOT Source
  49. Swift-BAT detection of GRB 050331
  50. GRB 050326: Early observations with Swift-UVOT
  51. GRB 050326 XMM-Newton observation
  52. GRB 050326: Swift XRT Position
  53. GRB 050326 BAT refined analysis
  54. GRB050326: delayed XRT observation
  55. GRB050319, color indices
  56. GRB050319: optical observation, March 20-22
  57. GRB050319: RTT150 Optical Observations
  58. Swift-BAT trigger 112060 is not a real GRB
  59. GRB 050318: Swift-BAT refined analysis
  60. GRB050319: VLA Observations
  61. GRB050319: radio observation
  62. GRB 050319: Swift-UVOT detection of the afterglow
  63. GRB 050315: Variability Analysis of Swift BAT Time History
  64. GRB050319: Radio Observations
  65. GRB 050319: NIR afterglow candidate
  66. GRB 050319:Near IR afterglow
  67. GRB 050318: SWIFT-UVOT refined analysis
  68. GRB 050319 : Confirmation of optical afterglow decay
  69. GRB 050319: Swift-BAT refined analysis
  70. GRB050319,optical observation
  71. GRB 050318: Swift/UVOT detection of afterglow emission
  72. RXTE Observations of GRB050318
  73. GRB050223: analysis of the XMM-Newton observation
  74. GRB050316: MASTER before, simultanious and follow up optical
  75. GRB 050306: ROTSE-III early limits
  76. GRB050316: MASTER optical observations
  77. GRB 050315: Swift-BAT further refined analysis
  78. GRB 050315 I-band observations
  79. GRB050315: Radio afterglow
  80. GRB050315: Swift-BAT Refined analysis
  81. Non-detection of GRB050315 in ATCA Radio Observations
  82. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  83. GRB 050315: Early Observations with Swift/UVOT
  84. GRB 050306: Radio Observations
  85. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  86. GRB 050306: optical afterglow
  87. Swift-BAT trigger 107873: No Swift XRT counterpart
  88. GRB 050306: Confirmation of X-ray afterglow
  89. GRB 050306: further TAROT optical data
  90. GRB050309: Early optical limit from P60
  91. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  92. GRB 050309 : Lulin R-band observation
  93. Swift 107873: P60 Optical Observations
  94. GRB 050306: R-band observations
  95. GRB 050306: REM optical-infrared observations
  96. GRB 050306: Possible X-ray Afterglow Position from the Swift
  97. GRB 050306: TAROT optical observations
  98. GRB 050306,optical observation
  99. Ongoing activity of SGR 1806-20 after the giant flare
  100. GRB050215B: Late-Time Swift UVOT Observations

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