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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').
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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"

11539 results found.

  1. IceCube-260930A - IceCube observation of a high-energy neutrino candidate track-like event
  2. GRB 260926C: AstroSat CZTI detection
  3. GRB 260926C: GECAM-B observation
  4. GRB 260926A: GECAM-B observation
  5. GRB 260926B: Glowbug gamma-ray detection of a likely short burst
  6. GRB 260926A: Glowbug gamma-ray detection
  7. GRB 260924A: VLA detection
  8. GRB 260924A: AbAO optical observations
  9. Fermi GRB 260928A: Global MASTER-Net observations report
  10. GRB 260928A: Fermi GBM Final Real-time Localization
  11. GRB 260924A: Upper limits from a neutrino search with IceCube
  12. Fermi GRB 260926C: Global MASTER-Net observations report
  13. GRB 260926C: Fermi GBM Final Real-time Localization
  14. GRB260914A: MAO/AZT-22 optical observations
  15. GRB 260926B: Fermi GBM Final Real-time Localization
  16. Fermi GRB 260926A: Global MASTER-Net observations report
  17. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  18. GRB 260926A: Fermi GBM Final Real-time Localization
  19. Konus-Wind detection of GRB 260924A
  20. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  21. GRB 260923A: Glowbug gamma-ray detection
  22. GRB 260924A: Optical follow-up observations with Kinder
  23. GRB 260924A: SVOM/GRM observation
  24. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  25. GRB 260923A: Insight-HXMT/HE detection
  26. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  27. GRB 260924A: GROWTH-India Telescope optical observations
  28. GRB 260924A: NuSTAR detection of prompt emission
  29. Konus-Wind detection of GRB 260922A
  30. GRB 260922A: NuSTAR detection of prompt emission
  31. GRB 260921A: NuSTAR detection of prompt emission
  32. GRB 260921A: SVOM/GRM observation
  33. GRB 260924A: Fermi GRB Observation
  34. Konus-Wind detection of GRB 260921A (possible merger-origin)
  35. GRB 260924A: Fermi-LAT detection of a bright burst
  36. GRB 260924A: AstroSat CZTI detection
  37. GRB 260920A: SVOM/GRM observation
  38. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  39. GRB 260924A: Fermi GBM Final Real-time Localization
  40. Fermi GRB 260923A: Global MASTER-Net observations report
  41. GRB 260923A: Fermi GBM Final Real-time Localization
  42. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  43. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  44. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  45. GRB 260920A: Glowbug gamma-ray detection
  46. GRB 260918A: SVOM/ECLAIRs refined analysis
  47. GRB 260917C: AstroSat CZTI detection
  48. GRB 260921A: AstroSat CZTI detection
  49. GRB 260921B: Fermi GBM Final Localization
  50. GRB 260921A: Fermi GBM Observation
  51. GRB 260921A: Fermi GBM Final Real-time Localization
  52. GRB 260920A: AstroSat CZTI detection
  53. GRB 260920A: Fermi GBM Final Real-time Localization
  54. IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
  55. Fermi GBM Sub-Threshold Detection of GRB 260918A
  56. Konus-Wind detection of GRB 260916B (short/hard)
  57. GRB 260916B: Glowbug gamma-ray detection of a short burst
  58. IPN triangulation of GRB 260916B (short)
  59. GRB 260917C: Fermi GBM Final Real-time Localization
  60. GRB 260916B: Fermi GBM Detection
  61. GRB 260916B: Fermi GBM Final Localization
  62. GRB 260917A: Glowbug gamma-ray detection
  63. GRB 260915A: SVOM/ECLAIRs refined analysis
  64. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  65. GRB 260917A: Fermi GBM Final Real-time Localization
  66. Fermi trigger No 811304653: Global MASTER-Net observations report
  67. Fermi trigger No 811264269: Global MASTER-Net observations report
  68. IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
  69. GRB 260914A: SVOM/GRM observation
  70. GRB 260914A: Mondy and TShAO optical observations
  71. GRB 260914A: SVOM/ECLAIRs refined analysis
  72. GRB 260914A: REM optical/NIR observations
  73. Fermi GBM Sub-Threshold Detection of GRB 260915A
  74. Fermi GBM Sub-Threshold Detection of GRB 260914A
  75. GRB 260907A: SVOM/GRM observation
  76. GRB 260910B: GOTO tentative optical counterpart candidates
  77. GRB 260910B: Fermi GBM Final Real-time Localization
  78. GRB 260910A: Fermi GBM Final Real-time Localization
  79. Fermi trigger No 810554827: Global MASTER-Net observations report
  80. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  81. Fermi GRB 260907B: Global MASTER-Net observations report
  82. GRB 260907B: Fermi GBM Final Real-time Localization
  83. Fermi GRB 260907A: Global MASTER-Net observations report
  84. GRB 260907A: Fermi GBM Final Real-time Localization
  85. GRB 260831A: GECAM-B observation
  86. GRB 260827A: Insight-HXMT/HE detection
  87. Konus-Wind detection of GRB 260829A
  88. GRB 260829A: SVOM/GRM observation
  89. GRB 260829A: AstroSat CZTI detection
  90. GRB 260827A: SVOM/GRM observation
  91. IPN triangulation of GRB 260829A
  92. GRB 260827A: Glowbug gamma-ray detection
  93. GRB 260831A: Fermi GBM Final Real-time Localization
  94. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  95. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  96. GRB 260829A: GECAM-B observation of a long burst
  97. GRB 260825A: SVOM/GRM observation of a long burst
  98. GRB 260825A: GECAM-B observation
  99. GRB 260829A: Fermi GBM Detection
  100. GRB 260825A: AstroSat CZTI detection

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