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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. GRB 090407: ROTSE-III Optical Limits
  2. GRB 090407: Swift detection of a burst
  3. GRB 090404: millimeter detection
  4. GRB 090404: nIR observations at Calar Alto
  5. GRB 090405: Fermi GBM Detection
  6. GRB 090403: Fermi GBM detection
  7. GRB 090404: GROND upper limits
  8. GRB 090404: further NOT observations
  9. Swift/UVOT observations of GRB090404
  10. GRB 090404: NOT observations
  11. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  12. GRB 090404: Swift-XRT Team refined analysis
  13. GRB 090404: Xinglong TNT optical Upper Limit
  14. GRB 090404: Swift-BAT refined analysis
  15. GRB 090404: Enhanced Swift-XRT position
  16. Fermi Gamma-ray Burst Monitor trigger 260428446 is not a GRB
  17. GRB 090404: Swift detection of a burst
  18. GRB 090401A: Suzaku WAM observation of the prompt emission
  19. GRB 090401B: Suzaku WAM observation of the prompt emission
  20. Konus-Wind observation of GRB 090401B
  21. GRB 090401B: Xinglong TNT optical Upper Limit
  22. GRB 090401B: VLA radio upper limit
  23. GRB 090401B: Upper limits of MITSuME optical observation
  24. GRB090401B, RIMOTS optical upper limits
  25. GRB 090401B: NOT optical observations
  26. GRB 090328: Fermi-LAT refined analysis
  27. Swift/UVOT observations of GRB090401B
  28. GRB 090401B: AGILE refined analysis
  29. Swift/UVOT observations of GRB090401B
  30. GRB 090401B: Swift XRT Refined Analysis
  31. GRB 090331: Fermi GBM detection
  32. Konus-Wind observation of GRB 090401A
  33. GRB 090401B: Enhanced Swift-XRT position
  34. AGILE Gamma-ray detection of GRB 090401B
  35. GRB 090401B: Swift-BAT refined analysis
  36. Swift/UVOT detection of GRB090401B
  37. GRB 090401B: Swift detection of a burst
  38. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  39. GRB 090401, Swift-BAT refined analysis
  40. GRB 090323: Further TLS detections - a break?
  41. GRB 090401: Swift detection of a burst
  42. GRB 090324: Suzaku WAM observation of the prompt emission
  43. GRB 090328: Radio afterglow detection
  44. GRB 090326: Fermi GBM detection
  45. GRB 090328: BOOTES-3 optical observations
  46. GRB 090328: Fermi GBM Spectral Analysis
  47. GRB 090328B: Fermi GBM Detection
  48. GRB 090330: Fermi GBM detection
  49. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  50. GRB 090328: Gemini South Redshift
  51. GRB 090328: Swift XRT refined analysis
  52. GRB090323: Optical observations from NOT
  53. Konus-Wind observation of GRB 090328
  54. GRB 090328: IPN Triangulation
  55. GRB 090328: Swift UVOT observations
  56. GRB 090323: WSRT Radio Detection
  57. GRB 090328: Updated position/optical afterglow candidate
  58. GRB 090328: Possible Swift/XRT detection
  59. Fermi LAT and GBM detections of GRB090328
  60. GRB 090323: Radio afterglow detection
  61. GRB 090323: Additional Lick observations
  62. GRB 090323: TLS detection at 5 days, no break
  63. GRB 090327: Fermi GBM detection
  64. GRB 090323: Faulkes Telescope South Observations
  65. GRB 090320B: MASTER-Net prompt optical observations
  66. GRB 090323: RTT150 optical observations
  67. GRB 090323: Lick observations
  68. GRB 090323: Fermi GBM Spectral Analysis
  69. GRB 090323: Optical observation of xinglong TNT
  70. GRB 090323 TLS detection - still bright
  71. GRB 090323: UVOT Detection of Afterglow
  72. GRB 090323: Swift-XRT refined analysis
  73. Konus-Wind observation of GRB 090323
  74. GRB 090324: SuperAGILE Localization of a Long GRB
  75. GRB 090323 Gemini-South Redshift
  76. GRB 090323: P60 Afterglow Confirmation
  77. GRB 090323: GROND Detection of the Afterglow and Photo-z
  78. SGR J1550-5418: two Fermi GBM triggers on March 22
  79. GRB 090323: Possible XRT Counterpart
  80. IPN triangulation of GRB090323
  81. GRB 090320C: Fermi GBM Detection
  82. Fermi GBM and LAT detections of GRB 090323
  83. GRB 090320B: Fermi GBM detection.
  84. GRB 090319: Fermi GBM detection
  85. GRB 090320A: Fermi GBM detection
  86. Further 15GHz observations of GRB090313
  87. GRB 090313: WSRT Radio Detection
  88. X-shooter observations of GRB 090313
  89. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  90. GRB 090315: Suzaku WAM observation of the prompt emission
  91. GRB 090313: VLT spectroscopy
  92. GRB090313: radio detection with the VLA
  93. Konus-Wind observation of GRB 090315
  94. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  95. GRB 090313, SMARTS optical/IR observations
  96. Further radio observation of GRB 090313
  97. Further Swift/UVOT observations of GRB 090313
  98. GRB 090313: detection with CARMA in 3mm band
  99. GRB090305B: MASTER-net prompt optical short burst observations
  100. Radio detection of GRB090313

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