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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"

24942 results found.

  1. GRB 050421: IR Observations
  2. GRB 050421: Swift-BAT refined analysis
  3. GRB050421
  4. GRB 050421: early Swift XRT analysis results
  5. GRB 050421: NIR observations
  6. GRB050421: P60 Observations
  7. GRB 050421: BOOTES-2 simultaneous optical observations
  8. GRB 050416b: Tentative Swift XRT Position
  9. GRB 050315: potential host galaxy
  10. GRB050326: analysis of the XMM-Newton observation
  11. GRB050418: Null Optical Observations
  12. GRB050416A, optical observations
  13. GRB 050418: Swift-BAT refined analysis
  14. GRB 050416: Mitsume optical observation
  15. GRB050416B: IR observations
  16. GRB050412: Radio Observations
  17. GRB 050416: Swift/UVOT detection of afterglow emission
  18. GRB050416: Refined Swift-XRT analysis
  19. GRB 050416,optical observation
  20. GRB050416: P200 NIR Observations
  21. GRB 050416: Radio observations
  22. Swift BAT/XRT Detection of GRB 050416
  23. GRB 050412: PROMPT VRcIc Observations
  24. GRB 050408: Kuiper 1.5m observations
  25. GRB 050412: early Swift XRT analysis results
  26. GRB 050412: Early Optical/Ultraviolet Observations with
  27. GRB 050408: SDSS Field Calibration
  28. GRB050412: P60 Observations
  29. GRB 050412: Swift XRT Position
  30. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  31. GRB 050412: IR and Optical observations
  32. GRB 050412: IR Observations
  33. GRB050408: Radio Observations
  34. GRB 050401: Optical limit
  35. GRB050410: P60 Observations
  36. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  37. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  38. GRB050410: Radio Observations
  39. GRB050410: MASTER optical observations
  40. GRB 050410: Early observations with Swift-UVOT
  41. Swift-BAT detection of GRB 050410
  42. GRB 050408: Inconsistency of host galaxy identification
  43. GRB 050408: Subaru Observations
  44. GRB 050408: WIDGET simultaneous optical observations
  45. GRB 050408: Properties of the Host Galaxy
  46. GRB050408: Radio Observations
  47. GRB 050408: Swift XRT analysis
  48. GRB 050408: Optical limit at 20 min after the burst
  49. GRB050408: REM NIR and Optical observation
  50. GRB 050408,optical observation
  51. GRB 050408: Mercator Optical Observations
  52. GRB 050408: Optical afterglow confirmed
  53. GRB 050408: opitcal observation
  54. GRB 050408, optical observations
  55. GRB 050408 optical candidate
  56. GRB 050408: Swift XRT Position
  57. GRB050408: MASTER optical observations
  58. GRB050401: Radio Detection
  59. GRB 050406: early Swift XRT analysis results
  60. GRB 050406 BAT refined analysis
  61. GRB 050406: Early observations with Swift-UVOT
  62. Swift-BAT detection of GRB 050406
  63. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  64. GRB 050401: VLT spectroscopic redshift
  65. GRB 050401 BAT refined analysis
  66. GRB050401: TNG R-band observation
  67. GRB 050402: Early observations with Swift-UVOT
  68. Swift Trigger 113225: P60 Observations
  69. GRB 050401: Optical afterglow confirmed
  70. GRB 050401: Prompt XRT position
  71. Retraction of three Swift GRB triggers
  72. GRB050331: No Afterglow Detected
  73. Swift-BAT detection of GRB 050331b
  74. GRB 050331: Swift UVOT Source
  75. Swift-BAT detection of GRB 050331
  76. GRB 050326: Early observations with Swift-UVOT
  77. GRB 050326 XMM-Newton observation
  78. GRB 050326: Swift XRT Position
  79. GRB 050326 BAT refined analysis
  80. GRB050326: delayed XRT observation
  81. GRB050319, color indices
  82. GRB050319: optical observation, March 20-22
  83. GRB050319: RTT150 Optical Observations
  84. Swift-BAT trigger 112060 is not a real GRB
  85. GRB 050318: Swift-BAT refined analysis
  86. GRB050319: VLA Observations
  87. GRB050319: radio observation
  88. GRB 050319: Swift-UVOT detection of the afterglow
  89. GRB 050315: Variability Analysis of Swift BAT Time History
  90. GRB050319: Radio Observations
  91. GRB 050319: NIR afterglow candidate
  92. GRB 050319:Near IR afterglow
  93. GRB 050318: SWIFT-UVOT refined analysis
  94. GRB 050319 : Confirmation of optical afterglow decay
  95. GRB 050319: Swift-BAT refined analysis
  96. GRB050319,optical observation
  97. GRB 050318: Swift/UVOT detection of afterglow emission
  98. RXTE Observations of GRB050318
  99. GRB050223: analysis of the XMM-Newton observation
  100. GRB050316: MASTER before, simultanious and follow up optical

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