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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"

33671 results found.

  1. GRB050416a: Radio Detection
  2. GRB 050422: Swift-UVOT observation
  3. GRB 050422: Swift-BAT refined analysis
  4. GRB 050422: Swift XRT Position
  5. Swift Detection of GRB 050422
  6. GRB 050421: NIR observations
  7. GRB 050416: Optical/NIR observations
  8. GRB 050421: SLOTIS observations
  9. GRB 050421: Further Analysis of IR imaging
  10. GRB050421: Radio Observations
  11. GRB050421: Radio Observations
  12. GRB 050421: Swift-UVOT observation
  13. GRB 050421: IR Observations
  14. GRB 050421: Swift-BAT refined analysis
  15. GRB 050421: ROTSE-III Optical Limits
  16. GRB 050421: NIR observations re-examination
  17. GRB 050421: early Swift XRT analysis results
  18. GRB 050421: NIR observations
  19. GRB050421: P60 Observations
  20. GRB 050421: BOOTES-2 simultaneous optical observations
  21. GRB 050421: Optical observations at the INT
  22. GRB 050416b: Tentative Swift XRT Position
  23. GRB 050315: potential host galaxy
  24. GRB 050412: Chandra observations
  25. GRB050416A, optical observations
  26. GRB 050418: Swift-BAT refined analysis
  27. Swift-BAT detection of the bright and long GRB 050418
  28. GRB 050416: Mitsume optical observation
  29. GRB 050416 : optical observation at Xinglong observatory
  30. GRB 050416B: optical observations
  31. GRB 050416b: Swift-BAT refined analysis
  32. GRB 050416b: LCO observations
  33. GRB 050416b: LCO observations
  34. GRB050416B: IR observations
  35. GRB 050416: Swift/UVOT refined analysis
  36. Swift-BAT detection of GRB 050416b
  37. IBAS GRB Alert # 2463: not a GRB
  38. GRB050412: Radio Observations
  39. GRB 050416: Swift/UVOT detection of afterglow emission
  40. GRB 050416: Swift-BAT refined analysis
  41. GRB 050416: ART observations
  42. GRB 050416,optical observation
  43. GRB 050416: KAIT observations
  44. GRB050416: P200 NIR Observations
  45. GRB 050416: Swift XRT Position
  46. GRB 050416: Radio observations
  47. Confirmation of OT for GRB050416
  48. GRB050416: P60 Afterglow Candidate
  49. Swift BAT/XRT Detection of GRB 050416
  50. GRB 050412: Subaru observations
  51. GRB 050408: RTT150 optical observations
  52. GRB 050412: PROMPT VRcIc Observations
  53. GRB 050408: Kuiper 1.5m observations
  54. GRB 050412: optical limit
  55. GRB 050412: optical observations
  56. GRB 050408: refined XRT analysis, no jet break seen yet
  57. GRB 050412: early Swift XRT analysis results
  58. GRB 050412 : XingLong optical observation
  59. GRB 050412: Swift-BAT refined analysis
  60. GRB 050412: ANU 2.3m observations
  61. GRB 050412: Early Optical/Ultraviolet Observations with
  62. GRB 050412: retraction of UVOT transient report
  63. GRB 050412: UVOT transient not in XRT error circle
  64. GRB 050408: SDSS Field Calibration
  65. GRB 050412: Optical limit
  66. GRB 050412: LCO Optical Observations
  67. GRB 050412: Optical observations
  68. GRB050412: P60 Observations
  69. GRB 050412: Swift XRT Position
  70. GRB050412: optical limit before and during GRB
  71. GRB 050412: LCO optical observations
  72. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  73. GRB 050412: IR and Optical observations
  74. GRB 050412: IR Observations
  75. GRB050408: Radio Observations
  76. GRB 050401: Optical limit
  77. GRB 050408: Optical limit
  78. GRB050410: P60 Observations
  79. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  80. GRB 050410, optical observations
  81. GRB 050408: PROMPT VRcIc Observations
  82. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  83. GRB 050410 R band Optical Observations
  84. GRB050410 : Null detection report
  85. GRB 050410, optical observations
  86. GRB050410: Radio Observations
  87. GRB 050408: Swift XRT measurement of possible jet break
  88. GRB050410: MASTER optical observations
  89. GRB 050410: Early observations with Swift-UVOT
  90. Swift-BAT detection of GRB 050410
  91. GRB 050410: Swift XRT Position
  92. GRB 050408: Retraction of Proposed Host Galaxy
  93. GRB 050408: Inconsistency of host galaxy identification
  94. GRB 050408: Subaru Observations
  95. GRB 050408: WIDGET simultaneous optical observations
  96. GRB 050408: SOAR UBVRc Observations
  97. GRB 050408: Properties of the Host Galaxy
  98. GRB 050408: Mercator Optical Observations
  99. GRB050408: Radio Observations
  100. GRB 050408: Swift XRT analysis

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