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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"

12274 results found.

  1. Fermi GRB 260926A: Global MASTER-Net observations report
  2. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  3. GRB 260926A: Fermi GBM Final Real-time Localization
  4. Konus-Wind detection of GRB 260924A
  5. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  6. GRB 260923A: Glowbug gamma-ray detection
  7. GRB 260924A: Optical follow-up observations with Kinder
  8. GRB 260924A: SVOM/GRM observation
  9. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  10. GRB 260923A: Insight-HXMT/HE detection
  11. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  12. GRB 260924A: GROWTH-India Telescope optical observations
  13. GRB 260924A: NuSTAR detection of prompt emission
  14. GRB 260921A: NuSTAR detection of prompt emission
  15. GRB 260921A: SVOM/GRM observation
  16. GRB 260924A: Fermi GRB Observation
  17. Konus-Wind detection of GRB 260921A (possible merger-origin)
  18. GRB 260924A: Fermi-LAT detection of a bright burst
  19. GRB 260924A: AstroSat CZTI detection
  20. GRB 260920A: SVOM/GRM observation
  21. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  22. GRB 260924A: Fermi GBM Final Real-time Localization
  23. Fermi GRB 260923A: Global MASTER-Net observations report
  24. GRB 260923A: Fermi GBM Final Real-time Localization
  25. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  26. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  27. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  28. GRB 260920A: Glowbug gamma-ray detection
  29. GRB 260918A: SVOM/ECLAIRs refined analysis
  30. GRB 260917C: AstroSat CZTI detection
  31. GRB 260921A: AstroSat CZTI detection
  32. GRB 260921B: Fermi GBM Final Localization
  33. GRB 260921A: Fermi GBM Observation
  34. GRB 260921A: Fermi GBM Final Real-time Localization
  35. GRB 260920A: AstroSat CZTI detection
  36. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 260920A: Fermi GBM Final Real-time Localization
  38. IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
  39. Fermi GBM Sub-Threshold Detection of GRB 260918A
  40. Konus-Wind detection of GRB 260916B (short/hard)
  41. GRB 260916B: Glowbug gamma-ray detection of a short burst
  42. IPN triangulation of GRB 260916B (short)
  43. GRB 260917C: Fermi GBM Final Real-time Localization
  44. GRB 260916B: Fermi GBM Detection
  45. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  46. GRB 260916B: Fermi GBM Final Localization
  47. GRB 260917A: Glowbug gamma-ray detection
  48. GRB 260915A: SVOM/ECLAIRs refined analysis
  49. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  50. GRB 260917A: Fermi GBM Final Real-time Localization
  51. Fermi trigger No 811304653: Global MASTER-Net observations report
  52. Fermi trigger No 811264269: Global MASTER-Net observations report
  53. IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
  54. GRB 260914A: SVOM/GRM observation
  55. GRB 260914A: Mondy and TShAO optical observations
  56. GRB 260914A: SVOM/ECLAIRs refined analysis
  57. GRB 260914A: REM optical/NIR observations
  58. Fermi GBM Sub-Threshold Detection of GRB 260915A
  59. Fermi GBM Sub-Threshold Detection of GRB 260914A
  60. GRB 260907A: SVOM/GRM observation
  61. GRB 260910B: GOTO tentative optical counterpart candidates
  62. GRB 260910B: Fermi GBM Final Real-time Localization
  63. GRB 260910A: Fermi GBM Final Real-time Localization
  64. Fermi trigger No 810554827: Global MASTER-Net observations report
  65. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  66. Fermi GRB 260907B: Global MASTER-Net observations report
  67. GRB 260907B: Fermi GBM Final Real-time Localization
  68. Fermi GRB 260907A: Global MASTER-Net observations report
  69. GRB 260907A: Fermi GBM Final Real-time Localization
  70. GRB 260831A: GECAM-B observation
  71. GRB 260827A: Insight-HXMT/HE detection
  72. Konus-Wind detection of GRB 260829A
  73. GRB 260829A: SVOM/GRM observation
  74. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  75. GRB 260829A: AstroSat CZTI detection
  76. GRB 260827A: SVOM/GRM observation
  77. IPN triangulation of GRB 260829A
  78. GRB 260827A: Glowbug gamma-ray detection
  79. GRB 260831A: Fermi GBM Final Real-time Localization
  80. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  81. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  82. GRB 260829A: GECAM-B observation of a long burst
  83. GRB 260825A: SVOM/GRM observation of a long burst
  84. GRB 260825A: GECAM-B observation
  85. GRB 260829A: Fermi GBM Detection
  86. GRB 260825A: AstroSat CZTI detection
  87. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  88. GRB 260829A: Fermi GBM Final Real-time Localization
  89. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  90. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  91. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  92. Fermi GBM trigger 809666623/260829141 is not a GRB
  93. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  94. GRB 260827A: Fermi GBM Final Real-time Localization
  95. IceCube-260825A: No transient candidates from the Zwicky Transient Facility
  96. GRB 260809A: SVOM/ECLAIRs refined analysis
  97. IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
  98. GRB 260825A: Fermi GBM Final Real-time Localization
  99. IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
  100. GRB260822B: Fermi GBM Final Localization

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