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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28255 results found.

  1. GRB 230307A: Erratum of the GCN 33441
  2. GRB 230204B: MASTER detection of an object near NTT Optical Afterglow Candidate
  3. GRB 230308A: Fermi GBM detection
  4. GRB 230307A: Possible optical afterglow
  5. GRB 230307A: ASO-S/HXI detection
  6. GRB 230307A: AstroSat LAXPC detection
  7. GRB 230228A: NUTTelA-TAO / BSTI Optical Limits
  8. GRB 230308A: AGILE/MCAL detection
  9. GRB 230307A: optical upper limit
  10. GRB 230217A: ATCA rapid-response radio detection
  11. Swift Trigger 1159108 is not a GRB
  12. GRB 230307A: Swift/BAT upper limits on the early afterglow
  13. GRB 230307A: Swift-XRT observations
  14. Konus-Wind detection of GRB 230307A
  15. GRB 230228A: VIRT Optical Upper Limit
  16. GRB 230307A: VZLUSAT-2 detection
  17. GRB 230304B: CALET Gamma-Ray Burst Monitor detection
  18. GRB 230308A: Fermi GBM Final Real-time Localization
  19. GRB 230307A: Tiled Swift observations
  20. GRB 230307A: Detection by GRBAlpha
  21. GRB 230305A: Detection by GRBAlpha
  22. GRB 230307A: AstroSat CZTI detection
  23. GRB 230307A: possibly the second highest GRB energy fluence ever identified
  24. IPN triangulation of GRB 230307A (long/very bright)
  25. GRB 230307A: AGILE/MCAL detection
  26. GRB 230307A: Fermi GBM detection of a very bright GRB
  27. GRB 230307A: GECAM detection of an extremely bright burst
  28. GRB 230307A: Fermi GBM Final Real-time Localization
  29. IceCube-230306A - IceCube observation of a high-energy neutrino candidate
  30. GRB 230304C: AstroSat CZTI detection
  31. GRB 230304B: AstroSat CZTI detection
  32. GRB 230304A: AstroSat CZTI detection
  33. GRB 230304B: Detection by GRBAlpha
  34. GRB 230304C: Fermi GBM Final Real-time Localization
  35. GRB 230304B: Fermi GBM Final Real-time Localization
  36. GRB 230304A: Fermi GBM Final Real-time Localization
  37. GRB 230228A: 6 GHz VLA radio upper limit
  38. GRB 230228A: Swift/UVOT Upper Limits
  39. GRB 230301B: Fermi GBM Final Real-time Localization
  40. GRB 230228A: OSN optical upper limit
  41. GRB 230301A: Fermi GBM Final Real-time Localization
  42. GRB 230228A: Swift-XRT refined Analysis
  43. GRB 230228A: Mondy optical upper limit
  44. GRB 230228A: Enhanced Swift-XRT position
  45. GRB 230228A: Nanshan/NEXT optical upper limit
  46. GRB 230228A: Miryang Arirang Astronomical Observatory (MAAO) 0.7-m telescope optical upper limit
  47. GRB 230228A: Prompt enhanced Swift-XRT position
  48. GRB 230228A: Swift detection of a possibly short burst
  49. GRB 230227A: Fermi GBM Final Real-time Localization
  50. GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
  51. GRB 230216A Mondy Observations
  52. GRB 230205A: VLA radio afterglow confirmation
  53. GRB 230217A: Swift/UVOT Upper Limits
  54. GRB 230216A: Swift/UVOT Upper Limits
  55. GRB 230217A: Continued Gemini Observations
  56. GRB 230222A: Fermi GBM Final Real-time Localization
  57. GRB 230217A: Swift-XRT afterglow detection
  58. GRB 230217A: AstroSat CZTI detection
  59. GRB 230217A: Gemini South optical upper limits
  60. GRB 230216B: CALET Gamma-Ray Burst Monitor detection
  61. GRB 230217A: 6 GHz VLA observations
  62. GRB 230220B: Fermi GBM Final Real-time Localization
  63. IceCube-230220A - IceCube observation of a high-energy neutrino candidate
  64. GRB 230220A: MAXI/GSC detection
  65. Konus-Wind detection of GRB 230217A
  66. GRB 230217A: Swift-XRT observations
  67. GRB 230218A: Fermi GBM Final Real-time Localization
  68. GRB 230217A: AGILE/MCAL detection
  69. GRB 230207B: CALET Gamma-Ray Burst Monitor detection
  70. GRB 230216B: AstroSat CZTI detection
  71. GRB 230216A: SVOM/C-GFT optical upper limit
  72. GRB 230217A: Swift detection of a short burst
  73. GRB 230217A: Fermi GBM Final Real-time Localization
  74. IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event
  75. GRB 230216A: Swift-XRT refined Analysis
  76. GRB 230205A: Lowell Discovery Telescope Observations
  77. GRB 230216A: Enhanced Swift-XRT position
  78. GRB 230216A: AKO Upper Limit
  79. GRB 230216A: Zadko observatory - Gingin optical observations
  80. GRB 230216A: Swift detection of a burst
  81. GRB 230215A: Fermi GBM Final Real-time Localization
  82. GRB 230209B: AGILE detection
  83. IPN triangulation of GRB 230209B
  84. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  85. GRB 230204B: ATCA radio detection
  86. Outburst from LS V +44 17 / RX J0440.9+4431: Transient detection by GRBAlpha
  87. GRB 230211A: Fermi GBM Final Real-time Localization
  88. GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
  89. Swift Trigger 1153670 is probably not a GRB
  90. GRB 230210A: Fermi GBM Final Real-time Localization
  91. GRB 230209B: Fermi GBM Final Real-time Localization
  92. GRB 230205A: 6 GHz VLA observations
  93. GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
  94. GRB 230209A: Fermi GBM Final Real-time Localization
  95. GRB 221009A: Continued Swift Observations
  96. GRB 230207B: Detection by GRBAlpha
  97. GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
  98. GRB 230204B: MASTER early OT detection
  99. GRB 230208A: Fermi GBM Final Real-time Localization
  100. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV

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