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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"

26286 results found.

  1. GRB 090408: Swift detection of a burst
  2. GRB 090407: Swift-XRT refined analysis
  3. GRB 090407: Swift UVOT Upper Limits
  4. GRB 090407: Swift-BAT refined analysis
  5. GRB 090407: ROTSE-III Optical Limits
  6. GRB 090407: Swift detection of a burst
  7. GRB 090405: Fermi GBM Detection
  8. GRB 090403: Fermi GBM detection
  9. Swift/UVOT observations of GRB090404
  10. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  11. GRB 090404: Swift-XRT Team refined analysis
  12. GRB 090404: Xinglong TNT optical Upper Limit
  13. GRB 090404: Swift-BAT refined analysis
  14. Fermi Gamma-ray Burst Monitor trigger 260428446 is not a GRB
  15. GRB 090404: Swift detection of a burst
  16. GRB 090401A: Suzaku WAM observation of the prompt emission
  17. GRB 090401B: Suzaku WAM observation of the prompt emission
  18. Konus-Wind observation of GRB 090401B
  19. GRB 090401B: Xinglong TNT optical Upper Limit
  20. GRB090401B, RIMOTS optical upper limits
  21. GRB 090328: Fermi-LAT refined analysis
  22. Swift/UVOT observations of GRB090401B
  23. GRB 090401B: AGILE refined analysis
  24. Swift/UVOT observations of GRB090401B
  25. GRB 090401B: Swift XRT Refined Analysis
  26. GRB 090331: Fermi GBM detection
  27. Konus-Wind observation of GRB 090401A
  28. GRB 090401B: Swift-BAT refined analysis
  29. GRB 090401B: Swift detection of a burst
  30. GRB 090401, Swift-BAT refined analysis
  31. GRB 090323: Further TLS detections - a break?
  32. GRB 090401: Swift detection of a burst
  33. GRB 090324: Suzaku WAM observation of the prompt emission
  34. GRB 090326: Fermi GBM detection
  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: Swift XRT refined analysis
  39. Konus-Wind observation of GRB 090328
  40. GRB 090328: Swift UVOT observations
  41. Fermi LAT and GBM detections of GRB090328
  42. GRB 090323: TLS detection at 5 days, no break
  43. GRB 090327: Fermi GBM detection
  44. GRB 090323: Lick observations
  45. GRB 090323: Optical observation of xinglong TNT
  46. GRB 090323 TLS detection - still bright
  47. GRB 090323: UVOT Detection of Afterglow
  48. Konus-Wind observation of GRB 090323
  49. GRB 090323 Gemini-South Redshift
  50. GRB 090323: GROND Detection of the Afterglow and Photo-z
  51. SGR J1550-5418: two Fermi GBM triggers on March 22
  52. GRB 090320C: Fermi GBM Detection
  53. Fermi GBM and LAT detections of GRB 090323
  54. GRB 090320B: Fermi GBM detection.
  55. GRB 090319: Fermi GBM detection
  56. GRB 090320A: Fermi GBM detection
  57. GRB 090315: Suzaku WAM observation of the prompt emission
  58. GRB090305B: MASTER-net prompt optical short burst observations
  59. GRB 090313: TAROT La Silla observatory optical detection
  60. GRB 090313: Zadko Telescope observations
  61. GRB 090313 - PAIRITEL NIR detections
  62. GRB 090313: Gemini-S redshift
  63. GRB 090313: Swift-XRT refined analysis
  64. GRB 090313: Swift/UVOT upper limits
  65. GRB 090313: Faulkes Telescope North observations
  66. GRB 090313: Swift-BAT refined analysis
  67. GRB 090313: Sustained optical brightness
  68. GRB 090313, GROND observations
  69. GRB 090313: Swift detection of a burst
  70. GRB 090313: Swift detection of a burst
  71. Swift trigger 346250 is probably not a burst
  72. GRB090310: Fermi GBM detection
  73. GRB 090205: Zadko Telescope late-time observations
  74. GRB 090309A: GROND upper limits
  75. GRB 090307A: TAROT Calern observatory optical observations
  76. GRB 090309: Swift/UVOT Upper Limits
  77. GRB090305B: Fermi GBM detection
  78. GRB 090309B: Fermi GBM detection
  79. GRB 090309: Swift-XRT refined analysis
  80. GRB 090309, Swift-BAT refined analysis
  81. GRB 090308: GROND observations
  82. GRB 090309: Swift detection of a burst
  83. GRB 090308B: Fermi GBM detection
  84. GRB 090308: Swift/UVOT Upper Limits
  85. GRB 090307B: Fermi GBM detection
  86. GRB 090306C: Fermi GBM detection
  87. GRB 090307: GROND Upper Limits
  88. GRB 090306B: GROND Upper Limits
  89. GRB 090305C: Suzaku WAM observation of the prompt emission
  90. GRB 090308: Swift-XRT refined analysis
  91. GRB 090308: Swift-BAT refined analysis
  92. GRB 090308: Swift detection of a burst
  93. GRB 090307: Swift-XRT afterglow confirmation and analysis
  94. GRB 090307: Swift-BAT refined analysis of trigger 345551
  95. Swift Trigger 345551 is probably not a GRB
  96. Swift-BAT trigger 345396 is not a GRB
  97. Fermi GBM trigger 090305784 is not a GRB
  98. GRB 090306: Swift detection of a possible burst
  99. GRB 090305: Swift/UVOT Upper Limits
  100. GRB 090305: Swift-XRT refined analysis

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