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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"
  1. Konus-Wind observation of GRB 101213A
  2. XRF 101117A, RIMOTS optical upper limits
  3. GRB 101213A: Fermi GBM observation
  4. GRB 101213A, Swift-BAT refined analysis
  5. GRB 101213A: Swift-XRT refined Analysis
  6. GRB 101213A: Swift/UVOT Upper Limits
  7. GRB 101213A: Enhanced Swift-XRT position
  8. GRB 101213: object within the X-ray error circle
  9. GRB 101213A: Swift detection of a burst
  10. GRB101204A: Swift/UVOT observations
  11. GRB 101204A: Swift-XRT refined Analysis
  12. GRB101204A GROND Detection of the Optical/NIR Afterglow
  13. GRB 101204A Afterglow Candidate, VATT Observations
  14. GRB 101129A : Suzaku WAM observation of the prompt emission
  15. GRB 101204A Swift-XRT/UVOT afterglow candidate
  16. Konus-Wind observation of GRB 101130A
  17. GRB 101204A detected in ground analysis of BAT data
  18. Konus-Wind observation of GRB 101129A
  19. IPN Localization of GRB101130 (possible short duration burst)
  20. GRB 101129A SHB found by IPN and in ground analysis of BAT data
  21. GRB101030A
  22. GRB 101201A: Fermi GBM observation
  23. GRB 101201A: Swift-XRT refined Analysis
  24. GRB 101201A: Swift/UVOT Detection
  25. GRB 101201A: GROND Detection of the Optical/NIR Afterglow
  26. GRB 101201A detected in ground analysis of BAT data
  27. Swift detection of MAXIJ1409-619
  28. GRB 101123A: ROTSE optical observations
  29. GRB 101123A: MASTER prompt optical observations
  30. Konus-Wind observation of GRB 101123A
  31. IPN triangulation of bright GRB 101123A
  32. GRB 101123A: Fermi GBM detection
  33. Optical observation of GRB 101024A
  34. GRB 101117B: GROND Upper limits
  35. GRB 101117B: Swift/UVOT Observations of the Optical Afterglow
  36. GRB 101112A: OSN and BTA observations
  37. XRF 101117A: Palomar Transient Factory Observations
  38. GRB 101117B: Swift-XRT refined analysis
  39. GRB101114A: Swift/UVOT Upper Limits
  40. GRB 101114A: Confirmation of the X-ray afterglow
  41. GRB 101117B: Swift-BAT refined analysis
  42. GRB 101117B: Enhanced Swift-XRT position
  43. GRB 101117B: Swift/UVOT Discovery of an Optical Afterglow
  44. GRB 101117B: Swift detection of a burst
  45. XRF101117A: MAXI/GSC detection of a short X-ray transient
  46. GRB 101114A: GROND Upper limits
  47. Konus-Wind observation of GRB 101114A
  48. Fermi GBM detection of a burst from a galactic source
  49. GRB 101114A: Swift-XRT candidate afterglow detection and analysis
  50. GRB 101114A, Swift-BAT GRB detected by ground processing
  51. Possible detection of INTEGRAL burst GRB 101112A by the EVLA
  52. GRB 101112A: Fermi GBM detection
  53. GRB 101112A: optical observations
  54. GRB 10112A: MASTER optical observations
  55. Konus-Wind observation of GRB 101112A
  56. GRB 101112A - XRT source detection/analysis
  57. GRB 101112A: BOOTES-2/TELMA optical afterglow candidate
  58. GRB101112A: Liverpool Telescope Afterglow Candidate
  59. GRB 101112A: a long GRB detected by INTEGRAL
  60. GRB 100906A: optical observations
  61. GRB 090113, the review of the sky area in plate archives
  62. GRB 101030A : MOA optical observation
  63. GRB 101030A: GROND optical/NIR afterglow candidate
  64. GRB 101030A : Swift XRT refined analysis
  65. GRB 101030A: Swift/UVOT Upper Limits
  66. GRB 101030A: Swift-BAT refined analysis
  67. GRB 101030A: Enhanced Swift-XRT position
  68. GRB 101030A: Swift detection of a burst
  69. GRB 090111, the review of the sky area in plate archives (1976-1996)
  70. Konus-Wind observation of GRB 101023A
  71. GRB 101024A: GROND optical/NIR observations
  72. GRB 101024A: Zadko observatory - Gingin. Optical observations refined analysis
  73. GRB 101024A: Swift XRT refined analysis
  74. GRB 101024A: Zadko observatory - Gingin. Optical observations
  75. GRB 101023A: miniTAO/ANIR NIR detection
  76. GRB 101024A: Fermi GBM observation
  77. GRB 101023A: Fermi GBM observation
  78. GRB101024A: Swift/UVOT
  79. GRB 101024A: Swift-BAT refined analysis
  80. GRB 101024A: GRAS06 optical observations
  81. GRB 101024A: Enhanced Swift-XRT position
  82. Swift/UVOT observations of GRB101023A
  83. GRB 101024A: Swift detection of a burst with an optical afterglow
  84. GGRB 101023A: GROND detection of the optical-NIR afterglow
  85. GRB 101023A: Swift-XRT Team Refined Analysis
  86. GRB 101023A: Swift-BAT refined analysis
  87. GRB 101023A: Gemini discovery of optical afterglow
  88. GRB 101023A: Enhanced Swift-XRT position
  89. GRB 101023A: REM NIR observations
  90. GRB 101023A: Swift detection of a burst
  91. GRB 101011A: miniTAO/ANIR NIR upper limits
  92. GRB 101020A: MASTER prompt and afterglow limit
  93. GRB 101020A: BOOTES2 follow-up and limit
  94. GRB 101020A: MASTER polarization optical observations
  95. GRB 101020A, Swift-BAT refined analysis
  96. GRB 101020A: Swift detection of a burst
  97. GRB 101017A: miniTAO/ANIR NIR upper limits
  98. GRB 101017A: Swift XRT refined analysis
  99. GRB 101017A: Swift/UVOT Observations
  100. GRB 101008A: correction to the GCN 11352

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