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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"

27046 results found.

  1. GRB 121011A Suzaku WAM observation of the prompt emission
  2. GRB 121012A: Fermi GBM detection
  3. PdB IRAM observation of GRB 121011A
  4. GRB 121014A: Swift-BAT refined analysis
  5. GRB 121014A: Swift detection of a burst
  6. INTEGRAL Alert n.6678: NOT A GRB
  7. GRB 121011A: Swift/UVOT Detection
  8. GRB 121011A: misprint in GCNC 13854
  9. GRB 121011A: Fermi GBM observation
  10. GRB 121011A: Fermi-LAT detection of a burst
  11. Swift-BAT trigger 535733 is not astrophysical
  12. GRB 121011A: Swift-XRT refined Analysis
  13. GRB 121011A: NOT optical observations
  14. GRB 121011A: optical observations
  15. GRB 121011A: MASTER-Net bell light curve
  16. GRB 121011A, Swift-BAT refined analysis
  17. Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
  18. GRB 121011A: Swift detection of a burst with optical afterglow
  19. Trigger 535747: Swift detection of an outburst from SGR1806-20
  20. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  21. GRB 120804A: Late-time Chandra observation
  22. GRB 121001A: GROND Afterglow Confirmation
  23. GRB 121001A: Swift/UVOT Upper Limits
  24. GRB 121001A: Swift-XRT refined Analysis
  25. Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
  26. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  27. GRB 121001A: possible optical counterpart
  28. Swift Trigger 535026: ROTSE-III Optical Limits
  29. Swift Trigger 535026: Galactic Transient or possible GRB
  30. GRB 120927A: Swift/UVOT Upper Limits
  31. GRB 120927A, Swift-BAT refined analysis
  32. GRB 120927A: GROND upper limits
  33. GRB 120927A: Swift-XRT refined Analysis
  34. GRB 120927A: Swift detection of a burst
  35. Further Swift-XRT observations of the GRB 120919A field.
  36. GRB 120923A: optical upper limit
  37. GRB 120921A: Fermi GBM detection of its 1000th GRB
  38. GRB 120923A: RAPTOR Early Afterglow Limits
  39. GRB 120916A Suzaku WAM observation of the prompt emission
  40. GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
  41. GRB 120923A: Swift-XRT refined Analysis
  42. GRB 120923A: GROND Upper limits
  43. GRB 120922A: GROND photometric redshift
  44. GRB 120922A: Fermi GBM detection
  45. GRB 120922A: Swift/UVOT Detection
  46. GRB 120923A: Swift-BAT refined analysis
  47. GRB 120922A: Swift-BAT refined analysis
  48. GRB 120923A: Swift/UVOT Upper Limit
  49. GRB 120922A: Swift-XRT refined Analysis
  50. GRB 120922A: Swift/UVOT Observations
  51. GRB 120922A: TAROT La Silla observatory optical observations
  52. GRB 120923A: TAROT La Silla observatory optical observations
  53. GRB 120923A: ROTSE-III Optical Limits
  54. GRB 120923A: Swift detection of a burst
  55. GRB 120922A: GROND afterglow candidate
  56. GRB 120922A: Swift detection of a burst
  57. GRB 120919B: MASTER prompt optical observations
  58. GRB 120919A: Swift/UVOT Upper Limits
  59. GRB 120919A: Swift-XRT observations
  60. IPN Triangulation of long GRB 120919B
  61. GRB 120919A: Fermi GBM detection
  62. GRB 120918A: Swift-BAT refined analysis
  63. Swift trigger 534017 was not an astrophysical event
  64. GRB 120916A: Fermi GBM Observation
  65. Swift Trigger 534017 is probably not real.
  66. GRB 120918A: Swift detection of a burst
  67. IPN Triangulation of long GRB 120916A
  68. GRB 120916A: Fermi-LAT detection of a burst
  69. Swift Transient Swift J174510.8-262411: Swift-BAT refined analysis
  70. Swift Trigger 533836 is a new Galactic transient
  71. GRB 120913B: Fermi GBM observation
  72. GRB 120913B: Swift-BAT refined analysis
  73. GRB 120913A: Fermi GBM observation
  74. GRB 120913B: FRAM early follow up and detection
  75. GRB 120913A: Swift-BAT refined analysis
  76. Continued Skynet/PROMPT observations of GRB120913B
  77. GRB 120913B: TAROT La Silla observatory optical detection
  78. Skynet/PROMPT observations of GRB120913B
  79. GRB 120913B: Swift detection of a burst
  80. GRB 120913A: Swift detection of a burst
  81. GRB 120907A: optical observations of ISON-Kislovodsk
  82. GRB 120911A: optical upper limit ISON-NM
  83. GRB 120911B: Fermi-LAT detection of a burst
  84. GRB 120911A: Fermi GBM observation
  85. GRB 120911A: Fermi/LAT upper limit
  86. GRB 120911A: Swift/UVOT Upper Limits
  87. GRB 120911A: Swift-XRT refined Analysis
  88. GRB 120911A: Swift-BAT refined analysis
  89. GRB 120911A: Faulkes Telescope North observations
  90. GRB 120911A: Swift-XRT observations
  91. GRB 120911A: ROTSE-III Optical Limits
  92. GRB 120911A: Swift detection of a burst
  93. GRB 120908A and GRB 120909A : Fermi/LAT upper limit
  94. GRB 120908A: Fermi GBM detection
  95. GRB 120908A: Swift Observations
  96. GRB 120909A: TAROT La Silla observatory optical observations
  97. GRB 120909A: Fermi GBM observation
  98. Konus-Wind observation of GRB 120909A
  99. GRB 120909A: Swift/UVOT Detection
  100. GRB 120909A: Swift-XRT refined Analysis

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