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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"

27041 results found.

  1. INTEGRAL Alert n.6678: NOT A GRB
  2. GRB 121011A: Swift/UVOT Detection
  3. GRB 121011A: misprint in GCNC 13854
  4. GRB 121011A: Fermi GBM observation
  5. GRB 121011A: Fermi-LAT detection of a burst
  6. Swift-BAT trigger 535733 is not astrophysical
  7. GRB 121011A: Swift-XRT refined Analysis
  8. GRB 121011A: NOT optical observations
  9. GRB 121011A: optical observations
  10. GRB 121011A: MASTER-Net bell light curve
  11. GRB 121011A, Swift-BAT refined analysis
  12. Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
  13. GRB 121011A: Swift detection of a burst with optical afterglow
  14. Trigger 535747: Swift detection of an outburst from SGR1806-20
  15. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  16. GRB 120804A: Late-time Chandra observation
  17. GRB 121001A: GROND Afterglow Confirmation
  18. GRB 121001A: Swift/UVOT Upper Limits
  19. GRB 121001A: Swift-XRT refined Analysis
  20. Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
  21. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  22. GRB 121001A: possible optical counterpart
  23. Swift Trigger 535026: ROTSE-III Optical Limits
  24. Swift Trigger 535026: Galactic Transient or possible GRB
  25. GRB 120927A: Swift/UVOT Upper Limits
  26. GRB 120927A, Swift-BAT refined analysis
  27. GRB 120927A: GROND upper limits
  28. GRB 120927A: Swift-XRT refined Analysis
  29. GRB 120927A: Swift detection of a burst
  30. Further Swift-XRT observations of the GRB 120919A field.
  31. GRB 120923A: optical upper limit
  32. GRB 120921A: Fermi GBM detection of its 1000th GRB
  33. GRB 120923A: RAPTOR Early Afterglow Limits
  34. GRB 120916A Suzaku WAM observation of the prompt emission
  35. GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
  36. GRB 120923A: Swift-XRT refined Analysis
  37. GRB 120923A: GROND Upper limits
  38. GRB 120922A: GROND photometric redshift
  39. GRB 120922A: Fermi GBM detection
  40. GRB 120922A: Swift/UVOT Detection
  41. GRB 120923A: Swift-BAT refined analysis
  42. GRB 120922A: Swift-BAT refined analysis
  43. GRB 120923A: Swift/UVOT Upper Limit
  44. GRB 120922A: Swift-XRT refined Analysis
  45. GRB 120922A: Swift/UVOT Observations
  46. GRB 120922A: TAROT La Silla observatory optical observations
  47. GRB 120923A: TAROT La Silla observatory optical observations
  48. GRB 120923A: ROTSE-III Optical Limits
  49. GRB 120923A: Swift detection of a burst
  50. GRB 120922A: GROND afterglow candidate
  51. GRB 120922A: Swift detection of a burst
  52. GRB 120919B: MASTER prompt optical observations
  53. GRB 120919A: Swift/UVOT Upper Limits
  54. GRB 120919A: Swift-XRT observations
  55. IPN Triangulation of long GRB 120919B
  56. GRB 120919A: Fermi GBM detection
  57. GRB 120918A: Swift-BAT refined analysis
  58. Swift trigger 534017 was not an astrophysical event
  59. GRB 120916A: Fermi GBM Observation
  60. Swift Trigger 534017 is probably not real.
  61. GRB 120918A: Swift detection of a burst
  62. IPN Triangulation of long GRB 120916A
  63. GRB 120916A: Fermi-LAT detection of a burst
  64. Swift Transient Swift J174510.8-262411: Swift-BAT refined analysis
  65. Swift Trigger 533836 is a new Galactic transient
  66. GRB 120913B: Fermi GBM observation
  67. GRB 120913B: Swift-BAT refined analysis
  68. GRB 120913A: Fermi GBM observation
  69. GRB 120913B: FRAM early follow up and detection
  70. GRB 120913A: Swift-BAT refined analysis
  71. Continued Skynet/PROMPT observations of GRB120913B
  72. GRB 120913B: TAROT La Silla observatory optical detection
  73. Skynet/PROMPT observations of GRB120913B
  74. GRB 120913B: Swift detection of a burst
  75. GRB 120913A: Swift detection of a burst
  76. GRB 120907A: optical observations of ISON-Kislovodsk
  77. GRB 120911A: optical upper limit ISON-NM
  78. GRB 120911B: Fermi-LAT detection of a burst
  79. GRB 120911A: Fermi GBM observation
  80. GRB 120911A: Fermi/LAT upper limit
  81. GRB 120911A: Swift/UVOT Upper Limits
  82. GRB 120911A: Swift-XRT refined Analysis
  83. GRB 120911A: Swift-BAT refined analysis
  84. GRB 120911A: Faulkes Telescope North observations
  85. GRB 120911A: Swift-XRT observations
  86. GRB 120911A: ROTSE-III Optical Limits
  87. GRB 120911A: Swift detection of a burst
  88. GRB 120908A and GRB 120909A : Fermi/LAT upper limit
  89. GRB 120908A: Fermi GBM detection
  90. GRB 120908A: Swift Observations
  91. GRB 120909A: TAROT La Silla observatory optical observations
  92. GRB 120909A: Fermi GBM observation
  93. Konus-Wind observation of GRB 120909A
  94. GRB 120909A: Swift/UVOT Detection
  95. GRB 120909A: Swift-XRT refined Analysis
  96. GRB 120909A: Swift-BAT refined analysis
  97. GRB 120909A: GROND detection of the afterglow
  98. Skynet/PROMPT Observations of GRB120909A
  99. GRB 120909A: Swift detection of a burst
  100. GRB 120907A: Swift/UVOT Detection

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