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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"

12279 results found.

  1. GRB 260924A: Upper limits from a neutrino search with IceCube
  2. Fermi GRB 260926C: Global MASTER-Net observations report
  3. GRB 260926C: Fermi GBM Final Real-time Localization
  4. GRB260914A: MAO/AZT-22 optical observations
  5. GRB 260926B: Fermi GBM Final Real-time Localization
  6. Fermi GRB 260926A: Global MASTER-Net observations report
  7. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  8. GRB 260926A: Fermi GBM Final Real-time Localization
  9. Konus-Wind detection of GRB 260924A
  10. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  11. GRB 260923A: Glowbug gamma-ray detection
  12. GRB 260924A: Optical follow-up observations with Kinder
  13. GRB 260924A: SVOM/GRM observation
  14. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  15. GRB 260923A: Insight-HXMT/HE detection
  16. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  17. GRB 260924A: GROWTH-India Telescope optical observations
  18. GRB 260924A: NuSTAR detection of prompt emission
  19. GRB 260921A: NuSTAR detection of prompt emission
  20. GRB 260921A: SVOM/GRM observation
  21. GRB 260924A: Fermi GRB Observation
  22. Konus-Wind detection of GRB 260921A (possible merger-origin)
  23. GRB 260924A: Fermi-LAT detection of a bright burst
  24. GRB 260924A: AstroSat CZTI detection
  25. GRB 260920A: SVOM/GRM observation
  26. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  27. GRB 260924A: Fermi GBM Final Real-time Localization
  28. Fermi GRB 260923A: Global MASTER-Net observations report
  29. GRB 260923A: Fermi GBM Final Real-time Localization
  30. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  31. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  32. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  33. GRB 260920A: Glowbug gamma-ray detection
  34. GRB 260918A: SVOM/ECLAIRs refined analysis
  35. GRB 260917C: AstroSat CZTI detection
  36. GRB 260921A: AstroSat CZTI detection
  37. GRB 260921B: Fermi GBM Final Localization
  38. GRB 260921A: Fermi GBM Observation
  39. GRB 260921A: Fermi GBM Final Real-time Localization
  40. GRB 260920A: AstroSat CZTI detection
  41. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  42. GRB 260920A: Fermi GBM Final Real-time Localization
  43. IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
  44. Fermi GBM Sub-Threshold Detection of GRB 260918A
  45. Konus-Wind detection of GRB 260916B (short/hard)
  46. GRB 260916B: Glowbug gamma-ray detection of a short burst
  47. IPN triangulation of GRB 260916B (short)
  48. GRB 260917C: Fermi GBM Final Real-time Localization
  49. GRB 260916B: Fermi GBM Detection
  50. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  51. GRB 260916B: Fermi GBM Final Localization
  52. GRB 260917A: Glowbug gamma-ray detection
  53. GRB 260915A: SVOM/ECLAIRs refined analysis
  54. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  55. GRB 260917A: Fermi GBM Final Real-time Localization
  56. Fermi trigger No 811304653: Global MASTER-Net observations report
  57. Fermi trigger No 811264269: Global MASTER-Net observations report
  58. IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
  59. GRB 260914A: SVOM/GRM observation
  60. GRB 260914A: Mondy and TShAO optical observations
  61. GRB 260914A: SVOM/ECLAIRs refined analysis
  62. GRB 260914A: REM optical/NIR observations
  63. Fermi GBM Sub-Threshold Detection of GRB 260915A
  64. Fermi GBM Sub-Threshold Detection of GRB 260914A
  65. GRB 260907A: SVOM/GRM observation
  66. GRB 260910B: GOTO tentative optical counterpart candidates
  67. GRB 260910B: Fermi GBM Final Real-time Localization
  68. GRB 260910A: Fermi GBM Final Real-time Localization
  69. Fermi trigger No 810554827: Global MASTER-Net observations report
  70. GRB 260907A: Glowbug gamma-ray detection of a likely short burst
  71. Fermi GRB 260907B: Global MASTER-Net observations report
  72. GRB 260907B: Fermi GBM Final Real-time Localization
  73. Fermi GRB 260907A: Global MASTER-Net observations report
  74. GRB 260907A: Fermi GBM Final Real-time Localization
  75. GRB 260831A: GECAM-B observation
  76. GRB 260827A: Insight-HXMT/HE detection
  77. Konus-Wind detection of GRB 260829A
  78. GRB 260829A: SVOM/GRM observation
  79. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  80. GRB 260829A: AstroSat CZTI detection
  81. GRB 260827A: SVOM/GRM observation
  82. IPN triangulation of GRB 260829A
  83. GRB 260827A: Glowbug gamma-ray detection
  84. GRB 260831A: Fermi GBM Final Real-time Localization
  85. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  86. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  87. GRB 260829A: GECAM-B observation of a long burst
  88. GRB 260825A: SVOM/GRM observation of a long burst
  89. GRB 260825A: GECAM-B observation
  90. GRB 260829A: Fermi GBM Detection
  91. GRB 260825A: AstroSat CZTI detection
  92. GRB 260829A: BALROG localization (Fermi Trigger 809676494 / GRB 260829256)
  93. GRB 260829A: Fermi GBM Final Real-time Localization
  94. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  95. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  96. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  97. Fermi GBM trigger 809666623/260829141 is not a GRB
  98. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  99. GRB 260827A: Fermi GBM Final Real-time Localization
  100. IceCube-260825A: No transient candidates from the Zwicky Transient Facility

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