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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"

27415 results found.

  1. GRB 090418: Swift XRT refined analysis
  2. GRB 090418A: ROTSE-III Refined Analysis
  3. GRB 090419: Swift detection of a burst
  4. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  5. GRB 090418: Swift-BAT refined analysis
  6. GRB 090417B: Swift-XRT refined analysis
  7. GRB 090417B: Swift-BAT further refined analysis
  8. GRB 090418: PAIRITEL NIR detection
  9. GRB 090418 Lick Redshift
  10. GRB 090418: ROTSE-III Confirmation of Optical Counterpart
  11. GRB 090418: Swift detection of a burst with optical afterglow
  12. GRB 090411B: Suzaku WAM observation of the prompt emission
  13. GRB 090411A: Suzaku WAM observation of the prompt emission
  14. GRB 090417B: Swift-BAT refined analysis
  15. GRB 090417A: Swift-BAT refined analysis
  16. GRB 090417A: Early-type nature of the putative host
  17. GRB 090417A: nearby galaxy redshift
  18. GRB 090417B: Swift detection of a burst
  19. GRB 090417: 2MASS galaxy within BAT Localization
  20. GRB 090417: Swift detection of a short burst
  21. GRB 090412: Fermi GBM detection
  22. GRB 090411B: Fermi GBM detection
  23. GRB 090411A: Fermi GBM detection
  24. GRB 090410: Suzaku WAM observation of the prompt emission
  25. GRB 090410: GROND upper limits
  26. Fermi GBM trigger 261106787 is not a GRB
  27. GRB 090410: MITSuME optical upper limits
  28. GRB 090410: Swift-BAT refined analysis
  29. GRB 090410: Swift detection of a burst
  30. GRB090408 : TAOS optical observations
  31. GRB 090409: Fermi GBM detection
  32. Swift-BAT Trigger 348781 is not a GRB
  33. Swift-BAT Trigger 348720 is not a GRB
  34. GRB090408, RIMOTS optical upper limits
  35. GRB 090408: Xinglong TNT optical Upper Limit
  36. Swift-BAT trigger 348781: almost certainly not a burst
  37. Fermi GBM Detection of a weak source
  38. GRB 090408B: MASTER II-Kourovka optical observations
  39. GRB 090408: Swift detection of a burst
  40. GRB 090407: Swift-XRT refined analysis
  41. GRB 090407: Swift UVOT Upper Limits
  42. GRB 090407: Swift-BAT refined analysis
  43. GRB 090407: ROTSE-III Optical Limits
  44. GRB 090407: Swift detection of a burst
  45. GRB 090405: Fermi GBM Detection
  46. GRB 090403: Fermi GBM detection
  47. Swift/UVOT observations of GRB090404
  48. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  49. GRB 090404: Swift-XRT Team refined analysis
  50. GRB 090404: Xinglong TNT optical Upper Limit
  51. GRB 090404: Swift-BAT refined analysis
  52. Fermi Gamma-ray Burst Monitor trigger 260428446 is not a GRB
  53. GRB 090404: Swift detection of a burst
  54. GRB 090401A: Suzaku WAM observation of the prompt emission
  55. GRB 090401B: Suzaku WAM observation of the prompt emission
  56. Konus-Wind observation of GRB 090401B
  57. GRB 090401B: Xinglong TNT optical Upper Limit
  58. GRB090401B, RIMOTS optical upper limits
  59. GRB 090328: Fermi-LAT refined analysis
  60. Swift/UVOT observations of GRB090401B
  61. GRB 090401B: AGILE refined analysis
  62. Swift/UVOT observations of GRB090401B
  63. GRB 090401B: Swift XRT Refined Analysis
  64. GRB 090331: Fermi GBM detection
  65. Konus-Wind observation of GRB 090401A
  66. GRB 090401B: Swift-BAT refined analysis
  67. GRB 090401B: Swift detection of a burst
  68. GRB 090401, Swift-BAT refined analysis
  69. GRB 090323: Further TLS detections - a break?
  70. GRB 090401: Swift detection of a burst
  71. GRB 090326: Fermi GBM detection
  72. GRB 090328B: Fermi GBM Detection
  73. GRB 090330: Fermi GBM detection
  74. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  75. GRB 090328: Swift XRT refined analysis
  76. Konus-Wind observation of GRB 090328
  77. GRB 090328: Swift UVOT observations
  78. Fermi LAT and GBM detections of GRB090328
  79. GRB 090323: TLS detection at 5 days, no break
  80. GRB 090327: Fermi GBM detection
  81. GRB 090320B: MASTER-Net prompt optical observations
  82. GRB 090323: Lick observations
  83. GRB 090323: Optical observation of xinglong TNT
  84. GRB 090323 TLS detection - still bright
  85. GRB 090323: UVOT Detection of Afterglow
  86. Konus-Wind observation of GRB 090323
  87. GRB 090323 Gemini-South Redshift
  88. GRB 090323: GROND Detection of the Afterglow and Photo-z
  89. SGR J1550-5418: two Fermi GBM triggers on March 22
  90. GRB 090320C: Fermi GBM Detection
  91. Fermi GBM and LAT detections of GRB 090323
  92. GRB 090320B: Fermi GBM detection.
  93. GRB 090319: Fermi GBM detection
  94. GRB 090320A: Fermi GBM detection
  95. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  96. GRB090305B: MASTER-net prompt optical short burst observations
  97. GRB 090313: TAROT La Silla observatory optical detection
  98. GRB 090313: Zadko Telescope observations
  99. GRB 090313 - PAIRITEL NIR detections
  100. GRB 090313: Gemini-S redshift

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