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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"

19190 results found.

  1. GRB060204B - SDSS pre-burst observations
  2. GRB 060203: Swift-BAT refined analysis
  3. GRB 060204B: Swift detection of a burst
  4. GRB 060203: RTT150 optical observations
  5. GRB060203: Swift XRT Team Refined Analysis
  6. GRB060203 - Swift UVOT observation
  7. Swift-BAT trigger is GRB 060203
  8. GRB060203: Observations with SARA
  9. GRB 060203: P60 Confirmation of Optical Afterglow
  10. Possible GRB 060203: candidate optical counterpart
  11. Swift BAT Trigger 180151: Swift XRT source detection
  12. Possible GRB 060203: optical observations at Asiago
  13. Swift-BAT trigger 180151 is unknown origin at this time
  14. GRB 060202: Refined analysis of the Swift-BAT burst
  15. GRB060202, optical observation
  16. GRB 060202: Swift/UVOT upper limits
  17. GRB 060202: Swift XRT Team Refined Analysis
  18. GRB060202: Faulkes North observation
  19. GRB 060202: Swift detection of a burst
  20. GRB 060130: Swift/XRT observation
  21. GRB 060123: VLA Radio Observations
  22. Possible GRB 051221B: MDM Correction
  23. GRB 060123: Swift refined analysis of an unusual GRB
  24. GRB060124, BVRcIc field calibration
  25. GRB060105: refined analysis of the Suzaku observation
  26. GRB 060124: HETE detection and spectrum of the main peak
  27. Konus-Wind observation of GRB 060124
  28. GRB060124: detailed XRT analysis
  29. GRB 060124 Optical Observations
  30. GRB 060124: R band Observations
  31. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  32. GRB 060123: Swift detection of a very long, faint burst
  33. GRB 060124: TAROT optical limits
  34. GRB 060124: Swift/UVOT Observation
  35. GRB 060124: Confirmation of the Afterglow
  36. GRB 060124: XRT position
  37. GRB 060124: Optical Observations at Tautenburg
  38. GRB 060117: Suzaku WAM observation of the prompt emission
  39. GRB060124:MASTER optical observation
  40. GRB 060111B: Suzaku WAM observation of the prompt emission
  41. GRB 060124: Swift-BAT detection of a burst
  42. GRB 060116: Radio Detection
  43. GRB 060116: MARGE optical observations
  44. GRB 060121: Swift/UVOT upper limits
  45. GRB 060121: Liverpool Telescopes optical limits
  46. GRB 060121: Swift XRT refined analysis
  47. GRB 060121: Swift XRT refined position
  48. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  49. Konus-Wind observation of GRB 060117
  50. GRB 060117: Refined analysis of the Swift-BAT burst
  51. GRB 060117: FRAM optical afterglow candidate
  52. GRB 060117: Swift-BAT detection of a bright burst
  53. GRB 060116: Refined analysis of the Swift-BAT burst
  54. GRB 060116: Swift/UVOT upper limits
  55. GRB060115: REM observations
  56. GRB 060110: XRT position and analysis
  57. GRB 060116: ROTSE-III Optical Limits
  58. GRB060116: XRT position
  59. GRB060116: Faulkes North observation
  60. GRB 060116: Swift-BAT detection of a burst
  61. GRB 060115: Refined analysis of the Swift-BAT burst
  62. GRB 060115: Swift/UVOT upper limits
  63. GRB 060115: Swift XRT refined analysis
  64. GRB 060114: Swift/UVOT Observations
  65. GRB 060115: MITSuME optical afterglow candidate
  66. GRB 060115: Swift detection of a burst
  67. GRB 060114: Swift XRT upper limit
  68. GRB 060110: KAIT observations
  69. GRB 060111B: Swift XRT refined analysis
  70. GRB 060111A: refined UVOT anaysis
  71. GRB 060111B: TAROT optical observation
  72. GRB060111A: RTT150 optical observations
  73. GRB060111B: RTT150, possible host galaxy
  74. GRB 060111B: Refined analysis of the Swift-BAT burst
  75. GRB 060110: MARGE observations
  76. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  77. GRB 060111B: Swift detection of a burst
  78. GRB 060111: Swift-BAT Refined Analysis
  79. GRB 060111: TAROT optical observation
  80. GRB 060111: possible UVOT counterpart
  81. GRB060111 : XRT refined analysis
  82. GRB 060111: ROTSE-III Optical Limits
  83. GRB 060111: Swift detection of a burst
  84. GRB 060110: Swift-BAT refined analysis
  85. GRB 060109: Swift-BAT refined analysis
  86. GRB 060110a: RAPTOR detection of early optical emission.
  87. Correction to GRB 060109 XRT analysis
  88. GRB 060110: Swift-BAT detection of a burst
  89. GRB 060109: Refined Swift-XRT analysis
  90. GRB 060109: Swift/UVOT upper limits
  91. Swift UVOT correction to GCN 4455
  92. GRB 060109: Swift Detection of a long burst
  93. GRB 060108: Refined XRT analysis
  94. GRB 060108: VLT J-band observations
  95. GRB 060108: Swift/UVOT upper limits
  96. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  97. GRB060108: Faulkes Telescope observation
  98. GRB 060108: Refined analysis of the Swift-BAT burst
  99. GRB 060108: Swift XRT position
  100. GRB060108: Swift detection of its 100th GRB

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