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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"

14834 results found.

  1. GRB 231222B: Swift-XRT afterglow detection
  2. GRB 231222B: Fermi GBM Detection
  3. GRB 231222B: Fermi-LAT detection
  4. IceCube-231211A: GRANDMA observations of PKS2047+098
  5. GRID detection of GRB 231215A
  6. GRB 231222A: Fermi GBM Final Real-time Localization
  7. GRB 231220A: Fermi GBM Final Real-time Localization
  8. GRB 231219A: Fermi GBM Final Real-time Localization
  9. GRID detection of GRB 231205B
  10. GRID detection of GRB 231205A
  11. GRB 231216A: 10.4 m GTC optical upper limit
  12. GRB 231215A: AMI-LA radio detection
  13. GRB 231216A: AST3-3 YaoAn Optical Upper Limit
  14. GRB 231216A: BOOTES-2/TELMA optical upper limit
  15. GRB 231215A: GRBAlpha detection
  16. GRB 231216A: Swift detection of a burst
  17. Konus-Wind detection of GRB 231215A
  18. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  19. GRB 231205B: VZLUSAT-2 detection
  20. GRB 231204A: VZLUSAT-2 detection
  21. GRB 231215A: CALET Gamma-Ray Burst Monitor detection
  22. GRB 231215A : OHP/T193 optical afterglow detection
  23. GRB 231215A: Swift/UVOT Detection
  24. GRB 231215A: BOOTES-4/MET optical detection
  25. GRB 231215A: AGILE detection
  26. Konus-Wind detection of GRB 231210B
  27. GRB 231215A: AstroSat CZTI detection
  28. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  29. GRB 231215A: Mondy optical bright afterglow detection
  30. GRB 231214A: AstroSat CZTI detection
  31. GRB 231215C: MASTER OT detection
  32. GRB 231215B: Fermi GBM Final Real-time Localization
  33. GRB 231215A: Swift detection of a burst
  34. GRB 231214A: Fermi-LAT detection
  35. GRB 231214B: Swift/BAT-GUANO detection of a burst
  36. GRB231214A: BOOTES-6/DPRT optical upper limit
  37. GRB 231214A: Swift detection of a burst
  38. GRB 231214A: Fermi GBM Final Real-time Localization
  39. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  40. IceCube-231211A - IceCube observation of a high-energy neutrino candidate track-like event
  41. GRB 231212A: GECAM-C detection of a likely short burst
  42. GRB 231210B: MeerLICHT afterglow observations
  43. GRB 231210B: VLT/X-shooter redshift
  44. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  45. GRB 231210B: Swift detection of a burst with optical counterpart
  46. Swift GRB231210.90: Global MASTER-Net OT detection
  47. IPN triangulation of GRB 231129C
  48. GRB 231210A: Fermi GBM Final Real-time Localization
  49. GRB 231208A: GRBAlpha detection
  50. GRB 231208A: Glowbug gamma-ray detection
  51. GRB 231208A: AstroSat CZTI detection of a faint burst
  52. IPN triangulation of GRB 231205A
  53. GRB 231205B: 1.3m DFOT Optical upper limit
  54. GRB 231205B: AGILE detection
  55. GRB 231206B: Fermi GBM Final Real-time Localization
  56. GRB 231205B: Ondrejov D50 optical upper limit
  57. GRB 231129C: ASIM MXGS observation and localization
  58. GRB 231206A: GECAM-B detection of a short burst (correction)
  59. GRB 231206A: GECAM-B detection of a short burst
  60. GRB 231205B: GECAM-B detection of a long burst
  61. GRB 231204A: Glowbug gamma-ray detection
  62. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  63. Fermi-LAT daily aperture light curve of T CrB now available
  64. GRB 231205B: Swift detection of a burst
  65. GRB 231204A: AstroSat CZTI detection
  66. GRB 231205A: GECAM-B detection of a short burst
  67. GRB 231205A: Fermi GBM Final Real-time Localization
  68. GRB 231204A: Fermi GBM Final Real-time Localization
  69. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  70. Konus-Wind detection of GRB 231129C
  71. IceCube-231202A - IceCube observation of a high-energy neutrino candidate track-like event
  72. The Fermi GBM team reports the detection of a likely SHORT GRB
  73. GRB 231203A: Fermi GBM Final Real-time Localization
  74. GRB 231129C: Swift-XRT afterglow detection
  75. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  76. GRB 231129A: VZLUSAT-2 detection
  77. GRB 231128A: VZLUSAT-2 detection
  78. GRB 231129C: AGILE detection
  79. GRB 231129C: MASTER OT detection
  80. GRB 231129A: BOOTES-5/JGT optical upper limit
  81. GRB 231129C: Fermi-LAT detection
  82. GRB 231129C: GRBAlpha detection
  83. GRB 231129C: Glowbug gamma-ray detection
  84. GRB 231129C: GECAM-B detection of a bright burst
  85. GRB 231129C: AstroSat CZTI detection
  86. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  87. GRB 231127A: GRBAlpha detection
  88. GRB 231129C: MAXI/GSC detection
  89. GRB 231129C: Fermi GBM detection of a very bright burst
  90. GRB 231129C: Fermi GBM Final Real-time Localization
  91. GRB 231129B: MAXI/GSC detection
  92. GRB 231129A: GECAM-C detection of a long burst
  93. GRB 231129A: INTEGRAL detection of a long GRB
  94. GRB 231129A: Swift detection of a burst
  95. GRB 231128A: Fermi GBM Final Real-time Localization
  96. GRB 231117A: MeerKAT 1.3GHz detection
  97. GRB 231127A: CALET Gamma-Ray Burst Monitor detection
  98. GRB 231125A: GRBAlpha detection
  99. GRB 231125A: CALET Gamma-Ray Burst Monitor detection
  100. GRB 231127A: AstroSat CZTI detection

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