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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"

19386 results found.

  1. GRB 050505, early TAROT observation
  2. GRB050509c: REM NIR and Optical observations
  3. GRB 050505: SARA Observations
  4. Swift UVOT Follow-up Observations of GRB 050509B
  5. GRB 050509A: Optical observations
  6. GRB050509b: Radio Observations
  7. GRB 050509B: ROTSE-III Optical Limits
  8. Swift Detection of GRB050509b: A short duration burst
  9. Swift Detection of the Burst GRB050509
  10. GRB 050505: Keck I-band Magnitude
  11. GRB 050505, simultaneous optical observation
  12. GRB 050505: Further Swift UVOT observations.
  13. GRB050505: AAVSO observations
  14. GRB050416A : 1 GHz limit from GMRT
  15. GRB 050505 UVOT
  16. GRB050505: Optical Afterglow Candidate
  17. GRB 050416b:Swift XRT afterglow upper limits
  18. GRB 050416b:Swift XRT afterglow upper limits
  19. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  20. GRB050502b: Afterglow Confirmation
  21. GRB050502: P200 Observations (Correction)
  22. GRB050502: P200 Observations
  23. Swift UVOT observation of GRB 050504
  24. GRB050504: P60 Observations
  25. GRB (?) 050504: IR Observations, Intriguing Source
  26. GRB 050502b, Optical observations
  27. GRB050502a: P60 Observations (Correction)
  28. GRB050502a: P60 Observations
  29. Renewal of SGR 1806-20 activity
  30. GRB050502A: Optical Observations
  31. GRB050502B Swift-BAT refined analysis
  32. GRB 050502b: Swift XRT Position
  33. Swift Detection of the Bright Burst GRB050502b
  34. GRB050502: ANU 1m optical Observations
  35. GRB 050502: ROTSE-III Detection of Possible Counterpart
  36. Swift/BAT possible detection of a weak burst GRB050430
  37. GRB050416a: Radio Detection
  38. GRB 050422: Swift-UVOT observation
  39. GRB 050422: Swift XRT Position
  40. Swift Detection of GRB 050422
  41. GRB 050421: SLOTIS observations
  42. GRB 050421: Further Analysis of IR imaging
  43. GRB050421: Radio Observations
  44. GRB050421: Radio Observations
  45. GRB 050421: IR Observations
  46. GRB 050421: ROTSE-III Optical Limits
  47. GRB050421
  48. GRB 050421: early Swift XRT analysis results
  49. GRB 050421: NIR observations
  50. GRB050421: P60 Observations
  51. GRB 050421: BOOTES-2 simultaneous optical observations
  52. Swift Detection of GRB050421
  53. GRB 050416b: Tentative Swift XRT Position
  54. GRB 050315: potential host galaxy
  55. GRB050326: analysis of the XMM-Newton observation
  56. GRB050418: Null Optical Observations
  57. GRB 050412: Chandra observations
  58. GRB050416A, optical observations
  59. GRB 050418: Swift-BAT refined analysis
  60. GRB 050416: Mitsume optical observation
  61. GRB 050416b: LCO observations
  62. GRB 050416b: LCO observations
  63. GRB050416B: IR observations
  64. GRB 050416: Swift/UVOT refined analysis
  65. Swift-BAT detection of GRB 050416b
  66. GRB050412: Radio Observations
  67. GRB 050416: Swift/UVOT detection of afterglow emission
  68. GRB050416: Refined Swift-XRT analysis
  69. GRB 050416,optical observation
  70. GRB050416: P200 NIR Observations
  71. GRB 050416: Swift XRT Position
  72. GRB 050416: Radio observations
  73. Swift BAT/XRT Detection of GRB 050416
  74. GRB 050412: Subaru observations
  75. GRB 050408: RTT150 optical observations
  76. GRB 050412: PROMPT VRcIc Observations
  77. GRB 050408: Kuiper 1.5m observations
  78. GRB 050412: optical observations
  79. GRB 050412: early Swift XRT analysis results
  80. GRB 050412: Swift-BAT refined analysis
  81. GRB 050412: Early Optical/Ultraviolet Observations with
  82. GRB 050408: SDSS Field Calibration
  83. GRB050412: P60 Observations
  84. GRB 050412: Swift XRT Position
  85. GRB050412: ROTSE-III Optical Limits
  86. GRB 050412: IR and Optical observations
  87. GRB 050412: IR Observations
  88. GRB050408: Radio Observations
  89. GRB050410: P60 Observations
  90. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  91. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  92. GRB050410: Radio Observations
  93. GRB050410: MASTER optical observations
  94. GRB 050410: Early observations with Swift-UVOT
  95. GRB 050410: Swift XRT Position
  96. GRB 050408: Inconsistency of host galaxy identification
  97. GRB 050408: Subaru Observations
  98. GRB 050408: WIDGET simultaneous optical observations
  99. GRB 050408: Properties of the Host Galaxy
  100. GRB050408: Radio Observations

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