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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"

23572 results found.

  1. GRB 090625B: Faulkes Telescope South observations
  2. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  3. GRB 090625B: a long GRB localized by INTEGRAL
  4. GRB 090625: Fermi GBM detection
  5. GRB 090618: Correction to GCN 9568
  6. GRB 090617: Suzaku WAM observation of the prompt emission
  7. GRB 090618: Suzaku WAM observation of the prompt emission
  8. GRB 090623: Fermi GBM detection
  9. GRB 090621B: I-band observations from 1.23m CAHA
  10. GRB 090621D: Fermi GBM detection
  11. GRB 090621B: Gemini spectrum of afterglow candidate
  12. GRB 090621C: Fermi GBM detection
  13. GRB 090621B: P60 Observations
  14. GRB 090620: Fermi GBM detecion
  15. Konus-Wind and Konus-RF observations of GRB 090618
  16. GRB 090621B: Swift-BAT refined analysis
  17. GRB 090621B: RTT150 optical observations
  18. GRB 090618: RTT150 optical observations
  19. GRB 090621A: Swift-BAT refined analysis
  20. GRB 090621B: Swift detection of a short hard burst
  21. GRB090618: Spectrum and photometry from 6.0m BTA
  22. GRB 090618: BOAO V-band Observation
  23. GRB 090621: Swift detection of a burst
  24. GRB 090618: Swift-BAT refined analysis
  25. GRB090618: Swift-XRT team refined analysis
  26. GRB 090618: AGILE observations
  27. GRB 090618: LOAO R-band Observation
  28. GRB 090618: Lick/KAST Spectroscopy
  29. GRB 090618: Swift detection of a bright burst with optical afterglow
  30. GRB 090612: Fermi GBM detection
  31. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  32. GRB 090602: Suzaku WAM observation of the prompt emission
  33. RXTE Discovery of Pulsations from SGR 0418+5729
  34. Konus-RF observation of SGR burst 090605A
  35. Discovery of a new soft gamma repeater source, SGR 0418+5729
  36. GRB 090608: Fermi GBM detection
  37. GRB 090607: Swift-BAT refined analysis of the SHB
  38. GRB 090607: Faulkes Telescope North observations
  39. GRB 090607: Swift detection of a burst
  40. GRB 090530B: Suzaku WAM observation of the prompt emission
  41. GRB 090530: RTT150 Optical Observation
  42. GRB 090529A: RTT150 Optical Observations
  43. GRB 090528: Suzaku WAM observation of the prompt emission
  44. GRB 090528B: Suzaku WAM observation of the prompt emission
  45. GRB090529B: ROVOR Upper Limits
  46. GRB 090531B: Swift/BAT spectral lag results
  47. GRB 090529C: Fermi GBM detection
  48. GRB 090529B: Fermi GBM detection
  49. GRB 090531B, RIMOTS optical upper limits
  50. GRB 090529: MITSuME optical observation
  51. GRB 090531B: Swift-BAT refined analysis
  52. GRB 090531B: Swift detection of a burst
  53. GRB 090531: Swift-BAT refined analysis
  54. GRB090530: R-band Observation
  55. GRB 090531: Swift detection of a burst
  56. GRB 090529: NOT optical observations
  57. GRB 090530: Swift-BAT refined analysis
  58. GRB 090530: GRAS002 refined OA analysis
  59. GRB 090530: PAIRITEL NIR Detections
  60. GRB 090530: Swift detection of a burst with an optical counterpart
  61. GRB 090529: optical observations
  62. GRB 090529: TLS Afterglow Observations
  63. GRB 090529: Swift-BAT refined analysis
  64. GRB 090529: Swift detection of a burst
  65. GRB 090520D: Fermi GBM detection
  66. GRB 090520C: Fermi GBM detection
  67. GRB 090520B: Fermi GBM detection
  68. GRB 090522 : Fermi GBM detection
  69. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  70. GRB 090513B: Fermi GBM detection
  71. GRB 090518: Fermi GBM detection
  72. GRB 090516C: Fermi GBM detection
  73. GRB 090520 Swift-BAT detection of a burst in ground analysis
  74. GRB 090516B: Fermi GBM detection
  75. GRB 090519: Swift-XRT refined analysis
  76. GRB 090519: GROND observation
  77. GRB 090519: Swift/UVOT Upper Limits
  78. GRB 090519, Swift-BAT refined analysis
  79. GRB 090519: TAROT Calern observatory optical observations
  80. GRB 090519: Swift detection of a burst
  81. GRB 090511: Fermi GBM Detection
  82. GRB 090514: Fermi GBM detection
  83. GRB 090518, Swift-BAT refined analysis
  84. GRB 090516, RIMOTS optical upper limits
  85. GRB090513: Fermi GBM detection
  86. GRB 090518: Swift detection of a burst
  87. GRB 090516: Swift-BAT refined analysis
  88. GRB 090516 - Zadko Telescope observations
  89. GRB 090516: Swift/UVOT Observations
  90. GRB 090516: Faulkes Telescope South optical afterglow
  91. GRB 090516: Swift detection of a burst
  92. GRB 090515: Lick Upper Limits
  93. GRB 090515: MMT/MMIRS NIR Upper Limit
  94. GRB 090515: Swift/UVOT Observations
  95. GRB 090515: Swift-BAT refined analysis
  96. GRB 090509 - Zadko Telescope observations
  97. GRB 090515: Gemini-N upper limit
  98. GRB 090515: Super-LOTIS Upper Limits
  99. GRB 090515: PAIRITEL Upper Limits
  100. GRB 090515: Swift detection of a short burst

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