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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 231204A: Glowbug gamma-ray detection
  2. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  3. Fermi-LAT daily aperture light curve of T CrB now available
  4. GRB 231205B: AKO Optical Upper Limit
  5. GRB 231205B: Swift detection of a burst
  6. GRB 231204A: AstroSat CZTI detection
  7. GRB 231205A: GECAM-B detection of a short burst
  8. GRB 231205A: Fermi GBM Final Real-time Localization
  9. GRB 231204A: Fermi GBM Final Real-time Localization
  10. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  11. Konus-Wind detection of GRB 231129C
  12. IceCube-231202A - IceCube observation of a high-energy neutrino candidate track-like event
  13. The Fermi GBM team reports the detection of a likely SHORT GRB
  14. GRB 231203A: Fermi GBM Final Real-time Localization
  15. GRB 231129C: Swift-XRT afterglow detection
  16. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  17. GRB 231129A: VZLUSAT-2 detection
  18. GRB 231129B: Swift-XRT observations
  19. GRB 231128A: VZLUSAT-2 detection
  20. GRB 231129C: AGILE detection
  21. GRB 231129A : MITSuME Akeno optical upper limits
  22. GRB 231129C: MASTER OT detection
  23. GRB 231129A: BOOTES-5/JGT optical upper limit
  24. GRB 231129C: Fermi-LAT detection
  25. GRB 231129A: JinShan optical upper limit
  26. GRB 231129C: GRBAlpha detection
  27. GRB 231129C: Glowbug gamma-ray detection
  28. GRB 231129C: Swift-XRT observations
  29. GRB 231129A: Swift/UVOT Upper Limits
  30. GRB 231129A: optical upper limit in Mondy observatory
  31. GRB 231129C: GECAM-B detection of a bright burst
  32. GRB 231129C: AstroSat CZTI detection
  33. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  34. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  35. GRB 231129C: Tiled Swift observations
  36. GRB 231127A: GRBAlpha detection
  37. GRB 231129C: MAXI/GSC detection
  38. GRB 231129C: Fermi GBM detection of a very bright burst
  39. GRB 231129A: Enhanced Swift-XRT position
  40. GRB 231129A: Swift-XRT refined Analysis
  41. GRB 231129C: Fermi GBM Final Real-time Localization
  42. GRB 231129B: Tiled Swift observations
  43. GRB 231129B: MAXI/GSC detection
  44. GRB 231129A: GECAM-C detection of a long burst
  45. GRB 231129A: INTEGRAL detection of a long GRB
  46. GRB 231129A: Swift detection of a burst
  47. GRB 231128A: Fermi GBM Final Real-time Localization
  48. GRB 231117A: MeerKAT 1.3GHz detection
  49. GRB 231127A: CALET Gamma-Ray Burst Monitor detection
  50. GRB 231125A: GRBAlpha detection
  51. GRB 231125A: CALET Gamma-Ray Burst Monitor detection
  52. GRB 231127A: AstroSat CZTI detection
  53. GRB 231125A (short): Glowbug gamma-ray detection
  54. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  55. GRB 231124A: GRBAlpha detection
  56. IceCube-231125A - IceCube observation of a high-energy neutrino candidate track-like event
  57. GRB 231125A: AstroSat CZTI detection of a short burst
  58. GRB 231126A: Fermi GBM Final Real-time Localization
  59. GRB 231123C: Insight-HXMT/HE detection
  60. GRB 231123C (short): Glowbug gamma-ray detection
  61. GRB 231124A: Glowbug gamma-ray detection
  62. GRB230728A: VIRT optical upper limit
  63. GRB230506B: VIRT optical upper limit
  64. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  65. GRB 231124A: CALET Gamma-Ray Burst Monitor detection
  66. GRB 231115A: XMM-Newton observation
  67. GRB 231124A: Fermi GBM Final Real-time Localization
  68. GRB 231123A: AstroSat CZTI detection
  69. GRB 231123C: Fermi GBM Final Real-time Localization
  70. GRB 231123B: Fermi GBM Final Real-time Localization
  71. GRB 231118A: REM optical afterglow detection
  72. GRB 231122B: AstroSat CZTI detection
  73. GRB 231122B: CALET Gamma-Ray Burst Monitor detection
  74. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  75. GRB 231117A: Chandra afterglow detection
  76. GRB 231123A: Fermi GBM Final Real-time Localization
  77. GRB 231122B: Glowbug gamma-ray detection
  78. GRB 231122A: GECAM detection
  79. GRB 231122B: GECAM detection
  80. GRB 231122A: Fermi GBM Final Real-time Localization
  81. GRB 231118A: ATCA detection of radio counterpart
  82. GRB 231117A: Swift/UVOT late time observations
  83. GRB 231118A: GRBAlpha detection
  84. GRB 231118A: VZLUSAT-2 detection
  85. GRB 231117A: AMI-LA radio observations
  86. Konus-Wind detection of GRB 231020A
  87. GRB 231117A: LDT Confirmation of Optical Fading
  88. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  89. GRB 231118B: CALET Gamma-Ray Burst Monitor detection
  90. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  91. 231118A: Swift-UVOT Detection
  92. GRB231117A: Swift-UVOT detection
  93. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  94. GRB 231118A: Fermi GBM observation
  95. GRB 231120A: Fermi GBM Final Real-time Localization
  96. GRB 231117A: Swift-XRT refined Analysis
  97. GRB 231118A: Swift-XRT refined Analysis
  98. GRB 231118A: MeerLICHT afterglow detection
  99. GRB 231117A: OHP/T120 optical observations
  100. GRB 231118A: VLT/X-shooter redshift

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