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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"

26329 results found.

  1. GRB 050416: Mitsume optical observation
  2. GRB050416B: IR observations
  3. GRB050412: Radio Observations
  4. GRB 050416: Swift/UVOT detection of afterglow emission
  5. GRB050416: Refined Swift-XRT analysis
  6. GRB 050416,optical observation
  7. GRB050416: P200 NIR Observations
  8. GRB 050416: Radio observations
  9. Swift BAT/XRT Detection of GRB 050416
  10. GRB 050412: PROMPT VRcIc Observations
  11. GRB 050408: Kuiper 1.5m observations
  12. GRB 050412: early Swift XRT analysis results
  13. GRB 050412: Early Optical/Ultraviolet Observations with
  14. GRB 050408: SDSS Field Calibration
  15. GRB050412: P60 Observations
  16. GRB 050412: Swift XRT Position
  17. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  18. GRB 050412: IR and Optical observations
  19. GRB 050412: IR Observations
  20. GRB050408: Radio Observations
  21. GRB 050401: Optical limit
  22. GRB050410: P60 Observations
  23. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  24. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  25. GRB050410: Radio Observations
  26. GRB050410: MASTER optical observations
  27. GRB 050410: Early observations with Swift-UVOT
  28. Swift-BAT detection of GRB 050410
  29. GRB 050408: Inconsistency of host galaxy identification
  30. GRB 050408: Subaru Observations
  31. GRB 050408: WIDGET simultaneous optical observations
  32. GRB 050408: Properties of the Host Galaxy
  33. GRB050408: Radio Observations
  34. GRB 050408: Swift XRT analysis
  35. GRB 050408: Optical limit at 20 min after the burst
  36. GRB050408: REM NIR and Optical observation
  37. GRB 050408,optical observation
  38. GRB 050408: Mercator Optical Observations
  39. GRB 050408: Optical afterglow confirmed
  40. GRB 050408: opitcal observation
  41. GRB 050408, optical observations
  42. GRB 050408 optical candidate
  43. GRB 050408: Swift XRT Position
  44. GRB050408: MASTER optical observations
  45. GRB050401: Radio Detection
  46. GRB 050406: early Swift XRT analysis results
  47. GRB 050406 BAT refined analysis
  48. GRB 050406: Early observations with Swift-UVOT
  49. Swift-BAT detection of GRB 050406
  50. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  51. GRB 050401: VLT spectroscopic redshift
  52. GRB 050401 BAT refined analysis
  53. GRB050401: TNG R-band observation
  54. GRB 050402: Early observations with Swift-UVOT
  55. Swift Trigger 113225: P60 Observations
  56. GRB 050401: Optical afterglow confirmed
  57. GRB 050401: Prompt XRT position
  58. Retraction of three Swift GRB triggers
  59. GRB050331: No Afterglow Detected
  60. Swift-BAT detection of GRB 050331b
  61. GRB 050331: Swift UVOT Source
  62. Swift-BAT detection of GRB 050331
  63. GRB 050326: Early observations with Swift-UVOT
  64. GRB 050326 XMM-Newton observation
  65. GRB 050326: Swift XRT Position
  66. GRB 050326 BAT refined analysis
  67. GRB050326: delayed XRT observation
  68. GRB050319, color indices
  69. GRB050319: optical observation, March 20-22
  70. GRB050319: RTT150 Optical Observations
  71. Swift-BAT trigger 112060 is not a real GRB
  72. GRB 050318: Swift-BAT refined analysis
  73. GRB050319: VLA Observations
  74. GRB050319: radio observation
  75. GRB 050319: Swift-UVOT detection of the afterglow
  76. GRB 050315: Variability Analysis of Swift BAT Time History
  77. GRB050319: Radio Observations
  78. GRB 050319: NIR afterglow candidate
  79. GRB 050319:Near IR afterglow
  80. GRB 050318: SWIFT-UVOT refined analysis
  81. GRB 050319 : Confirmation of optical afterglow decay
  82. GRB 050319: Swift-BAT refined analysis
  83. GRB050319,optical observation
  84. GRB 050318: Swift/UVOT detection of afterglow emission
  85. RXTE Observations of GRB050318
  86. GRB050223: analysis of the XMM-Newton observation
  87. GRB050316: MASTER before, simultanious and follow up optical
  88. GRB 050306: ROTSE-III early limits
  89. GRB050316: MASTER optical observations
  90. GRB 050315: Swift-BAT further refined analysis
  91. GRB 050315 I-band observations
  92. GRB050315: Radio afterglow
  93. GRB050315: Swift-BAT Refined analysis
  94. Non-detection of GRB050315 in ATCA Radio Observations
  95. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  96. GRB 050315: Early Observations with Swift/UVOT
  97. GRB 050306: Radio Observations
  98. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  99. GRB 050306: optical afterglow
  100. Swift-BAT trigger 107873: No Swift XRT counterpart

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