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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"

23601 results found.

  1. GRB 090423: Swift-XRT refined analysis
  2. GRB090423 - Swift/UVOT upper limits.
  3. GRB 090422: Swift-XRT refined analysis
  4. GRB090423, RIMOTS optical upper limits
  5. GRB 090423: Swift-BAT refined analysis
  6. GRB 090423: Faulkes Telescope South observations
  7. GRB 090423: Swift detection of a burst
  8. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  9. GRB 090422: Swift-BAT refined analysis
  10. GRB 090418B: RTT150 optical observations
  11. GRB 090418A: RTT150 optical observations
  12. GRB 090422: Liverpool Telescope observations
  13. GRB 090418B: Suzaku WAM observation of the prompt emission
  14. GRB 090422: Swift detection of a burst
  15. GRB 090418C: Fermi GBM Detection
  16. Swift-BAT trigger 349718 is not a burst
  17. GRB 090419: Swift/UVOT Observations
  18. GRB 090418B: Faulkes Telescope North observations
  19. GRB 090419: Swift-XRT refined analysis
  20. Konus-Wind observation of GRB 090418B
  21. GRB 090418: Erratum in GCN 9168
  22. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  23. GRB 090419: Swift-BAT refined analysis
  24. GRB 090418: Swift XRT refined analysis
  25. GRB 090419: Swift detection of a burst
  26. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  27. GRB 090418: Swift-BAT refined analysis
  28. GRB 090417B: Galaxy redshift
  29. GRB 090417B: Swift-BAT further refined analysis
  30. GRB 090418: PAIRITEL NIR detection
  31. GRB 090418 Lick Redshift
  32. GRB 090418: Swift detection of a burst with optical afterglow
  33. GRB 090411B: Suzaku WAM observation of the prompt emission
  34. GRB 090411A: Suzaku WAM observation of the prompt emission
  35. GRB 090417B: MITSuME Okayama optical upper limits
  36. GRB 090417B: Swift-BAT refined analysis
  37. GRB 090417A: Swift-BAT refined analysis
  38. GRB 090417B: Swift detection of a burst
  39. GRB 090417: Swift detection of a short burst
  40. GRB 090412: Fermi GBM detection
  41. GRB 090411B: Fermi GBM detection
  42. GRB 090411A: Fermi GBM detection
  43. GRB 090410: Suzaku WAM observation of the prompt emission
  44. GRB 090410: MITSuME optical upper limits
  45. GRB 090408b: IPN Triangulation
  46. GRB 090328b: IPN Triangulation
  47. GRB 090410: Swift-BAT refined analysis
  48. GRB 090410: Swift detection of a burst
  49. Konus-Wind and Konus-RF observations of GRB 090408b
  50. Swift-BAT Trigger 348781 is not a GRB
  51. Swift-BAT Trigger 348720 is not a GRB
  52. Swift-BAT trigger 348781: almost certainly not a burst
  53. GRB 090408B: MASTER II-Kourovka optical observations
  54. GRB 090408: Swift detection of a burst
  55. GRB 090407: GROND upper limits
  56. GRB 090407: Swift-BAT refined analysis
  57. Konus-Wind and Konus-RF observations of GRB 090406
  58. GRB 090407: Swift detection of a burst
  59. GRB 090404: millimeter detection
  60. GRB 090404: nIR observations at Calar Alto
  61. GRB 090403: Fermi GBM detection
  62. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  63. GRB 090404: Swift-BAT refined analysis
  64. GRB 090404: Swift detection of a burst
  65. GRB 090401A: Suzaku WAM observation of the prompt emission
  66. GRB 090401B: Suzaku WAM observation of the prompt emission
  67. Konus-Wind observation of GRB 090401B
  68. GRB 090401B: Upper limits of MITSuME optical observation
  69. GRB 090401B: AGILE refined analysis
  70. Konus-Wind observation of GRB 090401A
  71. AGILE Gamma-ray detection of GRB 090401B
  72. GRB 090401B: Swift-BAT refined analysis
  73. GRB 090401B: Swift detection of a burst
  74. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  75. GRB 090401, Swift-BAT refined analysis
  76. GRB 090323: Further TLS detections - a break?
  77. GRB 090401: Swift detection of a burst
  78. GRB 090324: Suzaku WAM observation of the prompt emission
  79. GRB 090326: Fermi GBM detection
  80. GRB 090328: BOOTES-3 optical observations
  81. GRB 090328: Fermi GBM Spectral Analysis
  82. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  83. GRB 090328: Gemini South Redshift
  84. Konus-Wind observation of GRB 090328
  85. GRB 090328: IPN Triangulation
  86. GRB 090328: Updated position/optical afterglow candidate
  87. GRB 090328: Possible Swift/XRT detection
  88. GRB 090323: Faulkes Telescope South Observations
  89. GRB 090320B: MASTER-Net prompt optical observations
  90. GRB 090323: RTT150 optical observations
  91. GRB 090323: Swift-XRT refined analysis
  92. Konus-Wind observation of GRB 090323
  93. GRB 090324: SuperAGILE Localization of a Long GRB
  94. GRB 090323: GROND Detection of the Afterglow and Photo-z
  95. GRB 090323: Possible XRT Counterpart
  96. IPN triangulation of GRB090323
  97. GRB 090320B: Fermi GBM detection.
  98. GRB 090319: Fermi GBM detection
  99. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  100. GRB 090315: Suzaku WAM observation of the prompt emission

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