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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"

19387 results found.

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

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