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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"

27323 results found.

  1. GRB 090417B: Swift detection of a burst
  2. GRB 090412: Fermi GBM detection
  3. GRB 090411B: Fermi GBM detection
  4. GRB 090411A: Fermi GBM detection
  5. GRB 090410: Suzaku WAM observation of the prompt emission
  6. GRB 090410: GROND upper limits
  7. GRB 090410: MITSuME optical upper limits
  8. GRB 090408b: IPN Triangulation
  9. GRB 090328b: IPN Triangulation
  10. GRB 090410: Swift-BAT refined analysis
  11. GRB 090409: Fermi GBM detection
  12. GRB090408, RIMOTS optical upper limits
  13. Swift-BAT trigger 348781: almost certainly not a burst
  14. GRB 090408B: MASTER II-Kourovka optical observations
  15. GRB 090407: GROND upper limits
  16. GRB 090407: VLT observations
  17. GRB 090407: Swift-XRT refined analysis
  18. GRB 090407: Swift UVOT Upper Limits
  19. GRB 090407: Enhanced Swift-XRT position
  20. GRB 090407: Swift-BAT refined analysis
  21. GRB 090407: ROTSE-III Optical Limits
  22. GRB 090407: Swift detection of a burst
  23. GRB 090404: millimeter detection
  24. GRB 090405: Fermi GBM Detection
  25. GRB 090403: Fermi GBM detection
  26. GRB 090404: GROND upper limits
  27. GRB 090404: further NOT observations
  28. Swift/UVOT observations of GRB090404
  29. GRB 090404: NOT observations
  30. GRB 090404: Swift-XRT Team refined analysis
  31. GRB 090404: Swift-BAT refined analysis
  32. GRB 090404: Enhanced Swift-XRT position
  33. GRB 090404: Swift detection of a burst
  34. GRB 090401A: Suzaku WAM observation of the prompt emission
  35. GRB 090401B: Suzaku WAM observation of the prompt emission
  36. GRB 090401B: Xinglong TNT optical Upper Limit
  37. GRB 090401B: VLA radio upper limit
  38. GRB 090401B: Upper limits of MITSuME optical observation
  39. GRB090401B, RIMOTS optical upper limits
  40. GRB 090401B: AGILE refined analysis
  41. GRB 090401B: Swift XRT Refined Analysis
  42. GRB 090331: Fermi GBM detection
  43. Konus-Wind observation of GRB 090401A
  44. GRB 090401B: Enhanced Swift-XRT position
  45. AGILE Gamma-ray detection of GRB 090401B
  46. GRB 090401B: Swift-BAT refined analysis
  47. GRB 090401B: Swift detection of a burst
  48. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  49. GRB 090401, Swift-BAT refined analysis
  50. GRB 090323: Further TLS detections - a break?
  51. GRB 090324: Suzaku WAM observation of the prompt emission
  52. GRB 090328: Radio afterglow detection
  53. GRB 090326: Fermi GBM detection
  54. GRB 090328: Fermi GBM Spectral Analysis
  55. GRB 090328B: Fermi GBM Detection
  56. GRB 090330: Fermi GBM detection
  57. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  58. GRB 090328: Swift XRT refined analysis
  59. GRB090323: Optical observations from NOT
  60. GRB 090328: Swift UVOT observations
  61. GRB 090328: Updated position/optical afterglow candidate
  62. Fermi LAT and GBM detections of GRB090328
  63. GRB 090323: Radio afterglow detection
  64. GRB 090327: Fermi GBM detection
  65. GRB 090320B: MASTER-Net prompt optical observations
  66. GRB 090323: Fermi GBM Spectral Analysis
  67. GRB 090323: UVOT Detection of Afterglow
  68. GRB 090324: SuperAGILE Localization of a Long GRB
  69. GRB 090323: P60 Afterglow Confirmation
  70. GRB 090323: GROND Detection of the Afterglow and Photo-z
  71. GRB 090323: Possible XRT Counterpart
  72. GRB 090320C: Fermi GBM Detection
  73. GRB 090320B: Fermi GBM detection.
  74. GRB 090319: Fermi GBM detection
  75. GRB 090320A: Fermi GBM detection
  76. Further 15GHz observations of GRB090313
  77. X-shooter observations of GRB 090313
  78. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  79. GRB 090315: Suzaku WAM observation of the prompt emission
  80. GRB090313: radio detection with the VLA
  81. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  82. Further radio observation of GRB 090313
  83. GRB 090313: detection with CARMA in 3mm band
  84. GRB090305B: MASTER-net prompt optical short burst observations
  85. GRB 090313: MITSuME Okayama observation
  86. GRB 090313: Additional Gemini-S photometry
  87. GRB 090313: TAROT La Silla observatory optical detection
  88. GRB 090313: Zadko Telescope observations
  89. GRB 090313 optical observations
  90. GRB 090313: Ongoing plateau phase
  91. GRB 090313: Swift-XRT refined analysis
  92. GRB 090313: Swift/UVOT upper limits
  93. GRB 090313: Swift-BAT refined analysis
  94. GRB 090313, GROND observations
  95. GRB 090309, Swift-BAT lag analysis
  96. Swift trigger 346250 is probably not a burst
  97. GRB090310: Fermi GBM detection
  98. GRB 090205: Zadko Telescope late-time observations
  99. GRB 090309A: GROND upper limits
  100. GRB 090307A: TAROT Calern observatory optical observations

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