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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"

26282 results found.

  1. GRB 090426B: Fermi GBM detection/observation
  2. GRB 090429B: Swift XRT refined analysis
  3. GRB 090428B: Fermi GBM detection
  4. GRB 090428: Fermi GBM detection
  5. GRB 090426: GAO 150cm telescope Optical Observation
  6. GRB 090429B: RIMOTS optical upper limits
  7. GRB 090429B: Swift-BAT refined analysis
  8. GRB 090429A: Swift-BAT refined analysis
  9. GRB 090426: YNAO-GMG observations
  10. GRB 090429B: GROND Observations
  11. GRB 090429B: Super-LOTIS early observations
  12. GRB 090429B: Swift detection of a burst
  13. GRB 090429: Swift detection of a burst
  14. GRB 090425: Fermi GBM detection
  15. GRB 090424: Suzaku WAM observation of the prompt emission
  16. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  17. GRB090426 Swift/UVOT observations
  18. GRB 090426 Keck LRIS redshift
  19. GRB 090426: Swift-BAT refined analysis
  20. GRB 090426: Swift-XRT refined analysis
  21. GRB 090423: GROND second epoch imaging and refined SED
  22. GRB 090426, RIMOTS optical upper limits
  23. GRB 090426: TNT confimation of optical counterpart
  24. GRB 090426: Swift detection of a burst with an optical counterpart
  25. GRB 090424: MASTER-Net prompt optical limit
  26. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  27. GRB 090424 Gemini-South Redshift
  28. GRB 090424 : TAOS optical detection
  29. GRB 090424: Swift-XRT refined analysis
  30. Swift/UVOT observations of GRB 090424
  31. GRB 090424: Swift-BAT refined analysis
  32. GRB 090424: Fermi GBM Observation
  33. GRB 090423: Fermi GBM observation
  34. GRB 090422: Fermi GBM observation
  35. GRB 090424: TNT optical observations
  36. GRB 090424: ROTSE-III Confimation of Optical Counterpart
  37. GRB 090424: Swift detection of a burst with an optical counterpart
  38. GRB 090423 limiting magnitudes
  39. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  40. GRB 090423: GROND detection and preliminary photo-z
  41. GRB 090423: NOT z-band limit
  42. GRB 090423: Swift-XRT refined analysis
  43. GRB090418A Rc-band photometry
  44. GRB090423 - Swift/UVOT upper limits.
  45. GRB 090422: Swift-XRT refined analysis
  46. GRB090423, RIMOTS optical upper limits
  47. GRB 090423: Swift-BAT refined analysis
  48. GRB 090422: Swift/UVOT Upper Limits
  49. GRB 090423: Faulkes Telescope South observations
  50. GRB 090423: Swift detection of a burst
  51. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  52. GRB 090422: Swift-BAT refined analysis
  53. GRB 080410: GAO 150cm telescope Optical Observation
  54. GRB 080408A: GAO 150cm telescope Optical Observation
  55. GRB 090422: Liverpool Telescope observations
  56. GRB 090418B: Suzaku WAM observation of the prompt emission
  57. GRB 090422: Swift detection of a burst
  58. GRB 090418C: Fermi GBM Detection
  59. Swift-BAT trigger 349718 is not a burst
  60. GRB 090419: Swift/UVOT Observations
  61. GRB 090418A: Swift/UVOT Observations
  62. GRB 090417B: Swift/UVOT Upper Limits
  63. GRB 090419: Swift-XRT refined analysis
  64. GRB 090419: GROND detection of afterglow candidate
  65. GRB 090419: Swift-BAT refined analysis
  66. GRB 090418: Swift XRT refined analysis
  67. GRB 090418A: ROTSE-III Refined Analysis
  68. GRB 090419: Swift detection of a burst
  69. GRB 090418: Swift-BAT refined analysis
  70. GRB 090417B: Swift-XRT refined analysis
  71. GRB 090417B: Swift-BAT further refined analysis
  72. GRB 090418: PAIRITEL NIR detection
  73. GRB 090418 Lick Redshift
  74. GRB 090418: ROTSE-III Confirmation of Optical Counterpart
  75. GRB 090418: Swift detection of a burst with optical afterglow
  76. GRB 090411B: Suzaku WAM observation of the prompt emission
  77. GRB 090411A: Suzaku WAM observation of the prompt emission
  78. GRB 090417B: Swift-BAT refined analysis
  79. GRB 090417A: Swift-BAT refined analysis
  80. GRB 090417B: Swift detection of a burst
  81. GRB 090417: Swift detection of a short burst
  82. GRB 090412: Fermi GBM detection
  83. GRB 090411B: Fermi GBM detection
  84. GRB 090411A: Fermi GBM detection
  85. GRB 090410: Suzaku WAM observation of the prompt emission
  86. Fermi GBM trigger 261106787 is not a GRB
  87. GRB 090410: Swift-BAT refined analysis
  88. GRB 090410: Swift detection of a burst
  89. GRB 090409: Fermi GBM detection
  90. Swift-BAT Trigger 348781 is not a GRB
  91. Swift-BAT Trigger 348720 is not a GRB
  92. GRB090408, RIMOTS optical upper limits
  93. GRB 090408: Xinglong TNT optical Upper Limit
  94. Swift-BAT trigger 348781: almost certainly not a burst
  95. Fermi GBM Detection of a weak source
  96. GRB 090408B: MASTER II-Kourovka optical observations
  97. GRB 090408: Swift detection of a burst
  98. GRB 090407: Swift-XRT refined analysis
  99. GRB 090407: Swift UVOT Upper Limits
  100. GRB 090407: Swift-BAT refined analysis

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