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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"

27052 results found.

  1. GRB 121202A: Swift-XRT refined Analysis
  2. GRB 121202A: Fermi GBM observation
  3. GRB 121202A: Swift-BAT refined analysis
  4. GRB 121202A: Swift-XRT observations
  5. GRB121202A: Swift/UVOT Observations
  6. GRB 121202A: TAROT Calern observatory optical observations
  7. GRB 121202A: Swift detection of a burst
  8. GRB 121201A: GROND afterglow observations and photometric redshift
  9. GRB 121201A: Swift/UVOT Detection
  10. GRB 121201A: Swift-XRT refined Analysis
  11. GRB 121201A: Swift-BAT refined analysis
  12. GRB 121201A: a GRB with an optical counterpart
  13. IPN Triangulation of GRB 121127A (short/hard)
  14. GRB 121128A: Swift/UVOT Detection
  15. GRB 121128A: Swift-XRT refined Analysis
  16. GRB 121122A: Fermi GBM observation
  17. GRB 121128A: RAPTOR Detection During Gamma-Ray Emitting Interval
  18. GRB 121128A: Fermi GBM observation
  19. GRB 121128A, Swift-BAT refined analysis
  20. Konus-Wind observation of GRB 121128A
  21. GRB 121128A: FTN optical afterglow confirmation
  22. GRB 121128A: Swift detection of a burst with an optical counterpart
  23. GRB 121123A: Suzaku WAM observation of the prompt emission
  24. GRB 121117A: Terskol obseravtions
  25. GRB 121123A: Swift/UVOT Observations
  26. GRB 121125A: Swift/UVOT Detection
  27. IPN Triangulation of GRB 121122A (long/intense)
  28. GRB 121118B: Suzaku WAM observation of the prompt emission
  29. GRB 121125A: Swift-XRT refined Analysis
  30. GRB 121125A: Fermi GBM Observation
  31. GRB 121125A: Swift-BAT refined analysis
  32. GRB 121125A: MASTER-NET optical observations
  33. GRB 121125A: Swift detection of a burst with optical counterpart
  34. GRB 121123A: GROND observations
  35. GRB 121123A: Swift-BAT refined analysis
  36. GRB 121123A: Swift-XRT refined Analysis
  37. GRB 121123A: optical observations
  38. GRB 121123A: NOT optical observations
  39. GRB 121123A: Fermi GBM observation
  40. GRB 121123A: Swift detection of a burst with optical counterpart
  41. Konus-Wind observation of GRB 121118B
  42. GRB 121117A: GROND confirmation of the UVOT afterglow candidate
  43. IPN Triangulation of GRB 121118A
  44. Swift-BAT trigger 538575 is not astrophysical
  45. GRB 121117A: Swift/UVOT Observations
  46. GRB 121117A: Swift-XRT refined Analysis
  47. GRB 121117A, Swift-BAT refined analysis
  48. GRB 121117A: ROTSE-III Optical Limits
  49. GRB 121117A: Swift detection of a burst
  50. Swift trigger 538575: Magellan Observations
  51. Fermi GBM trigger 121115.186 is not a GRB
  52. Trigger 538084: Swift detection of XTE J1739-302
  53. GRB 121108A: Swift-XRT refined Analysis
  54. GRB 121108A: Swift/UVOT Upper Limits
  55. GRB 121108A, Swift-BAT refined analysis
  56. GRB 121108A: Weihai observatory optical observations
  57. GRB 121108A: TAROT Calern observatory optical observations
  58. GRB 121108A: Swift detection of a burst
  59. GRB 121031A: Fermi GBM detection
  60. GRB 121028A: Swift/UVOT Upper Limits
  61. GRB 121031A, Early peak observed with Swift-BAT
  62. GRB 121102A: Swift/UVOT Upper Limits
  63. GRB 121031A: Swift/UVOT Upper Limits
  64. GRB 121031A: Swift-XRT refined Analysis
  65. GRB 121102A: Swift-XRT refined Analysis
  66. GRB 121102A: Swift-BAT refined analysis
  67. GRB 121029A Suzaku WAM observation of the prompt emission
  68. GRB 121102A: Swift detection of a burst
  69. GRB 121027A: sub-mm upper limit
  70. GRB 121031A: Swift-BAT refined analysis
  71. GRB 121031A: Swift detection of a burst
  72. GRB 121027A: Swift/UVOT Possible Detection
  73. GRB 121024A: LOAO RIzY Observation
  74. GRB 121027A: GROND Confirmation of Rebrightening
  75. GRB 121029A: Fermi GBM detection
  76. GRB 121028A: RAPTOR Limits During Gamma-Ray Emitting Interval
  77. GRB 121027A: MASTER early prompt optical limit
  78. GRB 121027A: Swift-XRT refined Analysis
  79. GRB 121028A: Swift-XRT refined Analysis
  80. GRB 121028A: Swift-BAT refined analysis
  81. GRB 121028A: Faulkes Telescope North observations
  82. GRB 121028A: Swift detection of a burst
  83. GRB 121027A: nIR afterglow candidate with AAT
  84. GRB 121027A: Swift-BAT refined analysis
  85. GRB 121025A: Swift-XRT observation
  86. GRB 121027A: MAXI/GSC detection 40 minutes after the Swift Trigger
  87. GRB 121027A: Swift detection of a burst
  88. Swift-BAT trigger 536502 is not astrophysical
  89. GRB 121024A: Swift/UVOT Observations
  90. GRB 121024A: Swift-BAT refined analysis
  91. GRB 121024A: GMG optical observation
  92. GRB 121024A: PAIRITEL NIR Detection
  93. GRB 121024A: Swift-XRT refined Analysis
  94. GRB 121024A: GROND Detection of the Optical/NIR Afterglow
  95. Skynet PROMPT/Dolomiti observations of GRB121024A
  96. GRB 121024A: BOOTES-1B optical detection
  97. GRB 121024A: TAROT Calern observatory optical detection of a bright counterpart
  98. GRB 121024A: Swift detection of a burst with an optical counterpart
  99. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  100. GRB 121017A: Swift/UVOT Upper Limits

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