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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"

19089 results found.

  1. GRB 050416b:Swift XRT afterglow upper limits
  2. GRB 050416b:Swift XRT afterglow upper limits
  3. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  4. GRB050502b: Afterglow Confirmation
  5. GRB050502: P200 Observations (Correction)
  6. GRB050502: P200 Observations
  7. Swift UVOT observation of GRB 050504
  8. GRB050504: P60 Observations
  9. GRB 050504: A long GRB detected with INTEGRAL
  10. GRB (?) 050504: IR Observations, Intriguing Source
  11. GRB 050502b, Optical observations
  12. GRB050502a: P60 Observations (Correction)
  13. GRB050502a: P60 Observations
  14. GRB050502B Swift-BAT refined analysis
  15. Swift Detection of the Bright Burst GRB050502b
  16. GRB 050502: ROTSE-III Detection of Possible Counterpart
  17. Swift/BAT possible detection of a weak burst GRB050430
  18. GRB050416a: Radio Detection
  19. Swift Detection of GRB 050422
  20. GRB 050421: SLOTIS observations
  21. GRB 050421: Further Analysis of IR imaging
  22. GRB050421: Radio Observations
  23. GRB050421: Radio Observations
  24. GRB 050421: IR Observations
  25. GRB050421
  26. GRB 050421: NIR observations
  27. GRB050421: P60 Observations
  28. GRB 050421: BOOTES-2 simultaneous optical observations
  29. GRB 050416b: Tentative Swift XRT Position
  30. GRB 050315: potential host galaxy
  31. GRB050326: analysis of the XMM-Newton observation
  32. GRB050418: Null Optical Observations
  33. GRB050416A, optical observations
  34. GRB 050418: Swift-BAT refined analysis
  35. GRB 050416: Mitsume optical observation
  36. GRB050416B: IR observations
  37. GRB050412: Radio Observations
  38. GRB 050416: Swift/UVOT detection of afterglow emission
  39. GRB 050416,optical observation
  40. GRB050416: P200 NIR Observations
  41. GRB 050416: Radio observations
  42. Swift BAT/XRT Detection of GRB 050416
  43. GRB 050408: Kuiper 1.5m observations
  44. GRB 050412: Swift-BAT refined analysis
  45. GRB 050412: Early Optical/Ultraviolet Observations with
  46. GRB 050408: SDSS Field Calibration
  47. GRB050412: P60 Observations
  48. GRB 050412: IR and Optical observations
  49. GRB 050412: IR Observations
  50. GRB050408: Radio Observations
  51. GRB 050408: Optical limit
  52. GRB050410: P60 Observations
  53. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  54. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  55. GRB050410: Radio Observations
  56. GRB 050408: Swift XRT measurement of possible jet break
  57. GRB050410: MASTER optical observations
  58. GRB 050410: Early observations with Swift-UVOT
  59. GRB 050408: Retraction of Proposed Host Galaxy
  60. GRB 050408: Inconsistency of host galaxy identification
  61. GRB 050408: Subaru Observations
  62. GRB 050408: WIDGET simultaneous optical observations
  63. GRB 050408: Properties of the Host Galaxy
  64. GRB 050408: Mercator Optical Observations
  65. GRB050408: Radio Observations
  66. GRB 050408: Swift XRT analysis
  67. GRB050408: REM NIR and Optical observation
  68. GRB 050408,optical observation
  69. GRB 050408: steepening of the optical decay
  70. GRB 050408: Optical afterglow confirmed
  71. GRB 050408: opitcal observation
  72. GRB 050408, optical observations
  73. GRB 050408: Swift XRT Position
  74. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  75. GRB050408: MASTER optical observations
  76. GRB050401: Radio Detection
  77. GRB 050406 BAT refined analysis
  78. GRB 050406: Early observations with Swift-UVOT
  79. Swift-BAT detection of GRB 050406
  80. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  81. GRB050401: TNG R-band observation
  82. GRB 050402: Early observations with Swift-UVOT
  83. Swift Trigger 113225: P60 Observations
  84. GRB 050401: Optical afterglow confirmed
  85. GRB050331: No Afterglow Detected
  86. GRB 050331: Swift UVOT Source
  87. GRB 050326: Early observations with Swift-UVOT
  88. GRB 050326 XMM-Newton observation
  89. GRB 050326: Swift XRT Position
  90. GRB050326: delayed XRT observation
  91. GRB050319, color indices
  92. GRB050319: optical observation, March 20-22
  93. GRB050319: RTT150 Optical Observations
  94. GRB050319: VLA Observations
  95. GRB050319: radio observation
  96. GRB 050319: Swift-UVOT detection of the afterglow
  97. GRB 050315: Variability Analysis of Swift BAT Time History
  98. GRB050319: Radio Observations
  99. GRB 050319: NIR afterglow candidate
  100. GRB 050319:Near IR afterglow

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