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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"

43612 results found.

  1. GRB 121024A: Swift-BAT refined analysis
  2. GRB 121024A: GMG optical observation
  3. GRB 121025A: MAXI/GSC detection
  4. GRB 121024A: Enhanced Swift-XRT position
  5. GRB 121024A: PAIRITEL NIR Detection
  6. GRB 121024A: Swift-XRT refined Analysis
  7. GRB 121024A: GROND Detection of the Optical/NIR Afterglow
  8. GRB 121024A: VLT/X-shooter redshift
  9. Skynet PROMPT/Dolomiti observations of GRB121024A
  10. GRB 121024A: BOOTES-1B optical detection
  11. GRB 121024A: TAROT Calern observatory optical detection of a bright counterpart
  12. GRB 121024A: Swift detection of a burst with an optical counterpart
  13. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  14. GRB 121011A: early optical light curve
  15. GRB 121017A: Swift/UVOT Upper Limits
  16. GRB 121017A: Swift-XRT refined Analysis
  17. GRB 121017A: GROND Observations
  18. GRB 121017A: Swift-BAT refined analysis
  19. GRB 121017A: Enhanced Swift-XRT position
  20. GRB 121017A: 1.23m CAHA R-band observations
  21. GRB 121017A optical observations
  22. GRB 121017A: BOOTES-2/TELMA observations
  23. GRB 121017A: Swift detection of a burst
  24. GRB 121011B: Suzaku WAM observation of the prompt emission
  25. GRB 121011A Suzaku WAM observation of the prompt emission
  26. GRB 121012A: Fermi GBM detection
  27. PdB IRAM observation of GRB 121011A
  28. Konus-Wind observation of GRB 121011B
  29. GRB 121014A: Swift-BAT refined analysis
  30. GRB 121011A: WSRT radio observation
  31. GRB 121014A: Swift detection of a burst
  32. INTEGRAL Alert n.6678: NOT A GRB
  33. GRB 121011A: Swift/UVOT Detection
  34. IPN Triangulation of short hard GRB 121011B
  35. GRB 121011A: NOT redshift retraction
  36. GRB 121011A: misprint in GCNC 13854
  37. GRB 121011A: Fermi GBM observation
  38. GRB 121011A: Fermi-LAT detection of a burst
  39. Swift-BAT trigger 535733 is not astrophysical
  40. GRB 121011A: Swift-XRT refined Analysis
  41. GRB 121011A: NOT optical observations
  42. GRB 121011A: optical observations
  43. GRB 121011A: MASTER-Net bell light curve
  44. GRB 121011A: TNG optical observations
  45. GRB 121011A, Swift-BAT refined analysis
  46. Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
  47. GRB 121011A: Enhanced Swift-XRT position
  48. Planned XMM-Newton and IRAM observation of GRB 121011A
  49. GRB 121011A: MASTER-Net early OT light curve
  50. GRB121011A : Xinglong TNT optical observation
  51. GRB 121011A: Swift detection of a burst with optical afterglow
  52. Trigger 535747: Swift detection of an outburst from SGR1806-20
  53. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  54. GRB 120927A: optical upper limit
  55. GRB 120804A: Late-time Chandra observation
  56. GRB 121001A: GROND Afterglow Confirmation
  57. GRB 121001A: Swift-XRT refined Analysis
  58. GRB 121001A: Enhanced Swift-XRT Position
  59. Swift Trigger 535026 is GRB 121001A: Swift-BAT refined analysis
  60. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  61. GRB 121001A: MASTER optical observations
  62. GRB 121001A: possible optical counterpart
  63. Swift Trigger 535026: ROTSE-III Optical Limits
  64. Swift Trigger 535026: Galactic Transient or possible GRB
  65. GRB 120927A: Swift/UVOT Upper Limits
  66. GRB 120927A, Swift-BAT refined analysis
  67. GRB 120927A: GROND upper limits
  68. GRB 120927A: Swift-XRT refined Analysis
  69. GRB 120927A: Enhanced Swift-XRT position
  70. GRB 120923A: JHK Observation
  71. GRB 120927A: Swift detection of a burst
  72. Further Swift-XRT observations of the GRB 120919A field.
  73. GRB 120923A: optical upper limit
  74. GRB 120921A: Fermi GBM detection of its 1000th GRB
  75. GRB 120916A Suzaku WAM observation of the prompt emission
  76. GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
  77. GRB 120923A: CARMA Observations
  78. GRB 120923A: EVLA Observations
  79. GRB 120923A: Swift-XRT refined Analysis
  80. GRB 120923A: GROND Upper limits
  81. GRB 120922A: GROND photometric redshift
  82. GRB 120922A: Fermi GBM detection
  83. GRB 120922A: Swift/UVOT Detection
  84. GRB 120923A: Swift-BAT refined analysis
  85. GRB 120922A: Swift-BAT refined analysis
  86. GRB 120923A: Swift/UVOT Upper Limit
  87. GRB 120922A: Swift-XRT refined Analysis
  88. GRB 120922A: Swift/UVOT Observations
  89. GRB 120923A: Gemini afterglow detection, high-z candidate
  90. GRB 120923A: Enhanced Swift-XRT position
  91. GRB 120922A: Enhanced Swift-XRT position
  92. GRB 120922A: TAROT La Silla observatory optical observations
  93. GRB 120923A: TAROT La Silla observatory optical observations
  94. GRB 120923A: ROTSE-III Optical Limits
  95. GRB 120923A: Swift detection of a burst
  96. GRB 120922A: GROND afterglow candidate
  97. GRB 120922A: Prompt enhanced Swift-XRT position
  98. GRB 120922A: Swift detection of a burst
  99. GRB 120919B: MASTER prompt optical observations
  100. GRB 120919A: Swift/UVOT Upper Limits

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