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

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