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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"

26269 results found.

  1. GRB 090628: Swift detection of a burst
  2. Fermi LAT observations of GRB 090626
  3. GRB 090625B: Fermi GBM observation
  4. GRB 090625B: Swift-XRT refined analysis
  5. GRB 090626: Fermi GBM detection
  6. GRB 090623: Suzaku WAM observation of the prompt emission
  7. GRB 090618: SARA Second Epoch Observations
  8. GRB 090625B: Faulkes Telescope South observations
  9. GRB 090625: Fermi GBM detection
  10. GRB 090617: Suzaku WAM observation of the prompt emission
  11. GRB 090618: Suzaku WAM observation of the prompt emission
  12. GRB 090623: Fermi GBM detection
  13. GRB 090621B: GRT Optical Observation
  14. GRB 090621A: GRT Optical Observation
  15. PAIRITEL observations of GRB 090618
  16. GRB 090621B: Fermi GBM detection
  17. GRB 090621D: Fermi GBM detection
  18. GRB 090621C: Fermi GBM detection
  19. GRB 090621: Fermi GBM observation
  20. GRB 090620: Fermi GBM detecion
  21. GRB 090621B: Swift/UVOT Upper Limits
  22. GRB 090621B: Swift-BAT refined analysis
  23. GRB 090621B: Swift-XRT refined analysis
  24. GRB 090621A: Swift-BAT refined analysis
  25. GRB 090621B: Swift detection of a short hard burst
  26. GRB 090621: Swift/UVOT Upper Limits
  27. GRB 090621: Swift-XRT Team refined analysis
  28. GRB 090618: BOAO V-band Observation
  29. GRB 090621: Swift detection of a burst
  30. GRB 090618: Fermi GBM observation
  31. GRB 090618, Swift-BAT refined spectral analysis
  32. GRB090618 - Continued optical monitoring and light curve break
  33. GRB 090618: Swift-BAT refined analysis
  34. GRB 090618: SARA observations
  35. GRB090618: Swift-XRT team refined analysis
  36. GRB090618: Swift/UVOT bright afterglow detection
  37. GRB 090617: Fermi GBM detection
  38. GRB 090618: LOAO R-band Observation
  39. GRB 090618 Faulkes Telescope North observations
  40. Optical observations of GRB 090618
  41. GRB 090618: OA behavior from KAIT
  42. GRB 090618: ROTSE-III Detection of Optical Counterpart
  43. GRB090618: P60 Optical Afterglow
  44. GRB 090618: Swift detection of a bright burst with optical afterglow
  45. GRB 090616: Fermi GBM detection
  46. GRB 090612: Fermi GBM detection
  47. GRB 090610C: Fermi GBM detection
  48. GRB 090610B: Fermi GBM detection
  49. GRB 090610: Fermi GBM detection
  50. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  51. GRB 090602: Suzaku WAM observation of the prompt emission
  52. GRB 090531B: Fermi GBM detection
  53. Discovery of a new soft gamma repeater source, SGR 0418+5729
  54. GRB 090608: Fermi GBM detection
  55. GRB 090606: Fermi GBM detection
  56. GRB 090607: XRT Team Refined Analysis
  57. GRB 090607: Swift/UVOT Upper Limits
  58. GRB 090607: Swift-BAT refined analysis of the SHB
  59. GRB 090607: Faulkes Telescope North observations
  60. GRB 090607: Swift detection of a burst
  61. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  62. GRB 090530B: Suzaku WAM observation of the prompt emission
  63. GRB 090530: RTT150 Optical Observation
  64. GRB 090602: Fermi GBM detection
  65. GRB 090529A: RTT150 Optical Observations
  66. GRB 090528: Suzaku WAM observation of the prompt emission
  67. GRB 090531B: GROND observation
  68. GRB 090528B: Suzaku WAM observation of the prompt emission
  69. GRB 090530: Early RAPTOR Optical Observations
  70. GRB090529B: ROVOR Upper Limits
  71. GRB 090529C: Fermi GBM detection
  72. GRB 090529B: Fermi GBM detection
  73. GRB 090530B: Fermi GBM detection
  74. Corrections to GRB 090531B Swift/UVOT Upper Limits
  75. GRB 090531B, RIMOTS optical upper limits
  76. GRB 090531B: Swift/UVOT Upper Limits
  77. GRB 090530: GRT Optical Observation
  78. GRB 090531B: Swift-BAT refined analysis
  79. Initial Swift/UVOT observations of GRB 090531B
  80. GRB 090531B: Swift-XRT candidate afterglow position
  81. GRB 090531B: ROTSE-III Optical Limits
  82. GRB 090531B: Swift detection of a burst
  83. GRB 090531: Swift-BAT refined analysis
  84. GRB 090530: break in light curve
  85. GRB 090531: GROND upper limits
  86. GRB 090531: P60 Observations
  87. GRB 090531: Swift detection of a burst
  88. GRB090530: Swift XRT refined analysis
  89. GRB090530: Swift/UVOT afterglow detection
  90. GRB 090529: Swift-XRT refined analysis
  91. GRB 090528B: Fermi GBM detection
  92. GRB 090528: Fermi GBM detection
  93. GRB 090530: Swift-BAT refined analysis
  94. GRB 090530: PAIRITEL NIR Detections
  95. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  96. GRB 090530: Swift detection of a burst with an optical counterpart
  97. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  98. GRB 090529: Swift-BAT refined analysis
  99. GRB 090529: Preliminary Swift/UVOT Upper Limit
  100. GRB 090529: Xinglong TNT optical observation

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