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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"

1542 results found.

  1. GRB 261020A: Insight-HXMT/HE detection
  2. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  3. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  4. GRB 261020A: Fermi GBM Observation
  5. IceCube-261020A - IceCube observation of a high-energy neutrino candidate track-like event
  6. GRB 261020A: MAXI GSC detection
  7. GRB 261020A: Fermi GBM Final Real-time Localization
  8. IceCube-261012A: Upper limits from a search for additional neutrino events in IceCube
  9. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  10. IceCube-260919A: No transient candidates from the Zwicky Transient Facility
  11. IceCube-261012A - IceCube observation of a high-energy neutrino candidate track-like event
  12. Fermi-LAT Gamma-ray Observations of IceCube-260930A
  13. IceCube-260930A: Upper limits from a search for additional neutrino events in IceCube
  14. IceCube-260930A - IceCube observation of a high-energy neutrino candidate track-like event
  15. IceCube Alert 260930A: Global MASTER-Net observations report
  16. GRB 260924A: Upper limits from a neutrino search with IceCube
  17. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  18. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  19. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  20. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  21. IceCube Alert 260919A: Global MASTER-Net observations report
  22. IceCube-260919A - IceCube observation of a high-energy neutrino candidate track-like event
  23. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  24. IceCube-260916A - IceCube observation of a high-energy neutrino candidate track-like event
  25. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  26. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  27. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  28. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  29. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  30. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  31. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  32. IceCube-260825A: No transient candidates from the Zwicky Transient Facility
  33. IceCube Alert 260825A: Global MASTER-Net observations report
  34. IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
  35. IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
  36. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  37. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  38. IceCube-260821A: Upper limits from a search for additional neutrino events in IceCube
  39. IceCube Alert 260821A: Global MASTER-Net observations report
  40. IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event
  41. IceCube-260807A: Upper limits from a search for additional neutrino events in IceCube
  42. IceCube-260805A: Upper limits from a search for additional neutrino events in IceCube
  43. IceCube Alert 260807A: Global MASTER-Net observations report
  44. IceCube-260805A: One candidate from the Zwicky Transient Facility
  45. IceCube-260807A - IceCube observation of a high-energy neutrino candidate track-like event
  46. GRB 260708A: cubesat Avion detection
  47. IceCube-260805A - IceCube observation of a high-energy neutrino candidate track-like event
  48. IceCube-Cascade 260801A: Upper limits from a search for additional neutrino events in IceCube
  49. Fermi-LAT Gamma-ray Observations of IceCube-260722A
  50. IceCube-260722A: Classification of ZTF26abjbxfs/SN 2026vts as a Type Ia Supernova
  51. IceCube-260722A: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-260722A: One candidate from the Zwicky Transient Facility (ZTF)
  53. IceCube Alert 260722A: Global MASTER-Net observations report
  54. IceCube-260722A - IceCube observation of a high-energy neutrino candidate track-like event
  55. IceCube-260708A: Follow-up studies of cosmic-ray origin of high-energy neutrino alert
  56. IceCube-260712A: No candidates with the Zwicky Transient Facility (ZTF)
  57. IceCube-260712A: Upper limits from a search for additional neutrino events in IceCube
  58. IceCube-260712A: LAST optical follow-up observations of the IceCube neutrino candidate
  59. Fermi-LAT Gamma-ray Observations of IceCube-260712A
  60. Fermi-LAT Gamma-ray Observations of IceCube-260708A
  61. Fermi-LAT Gamma-ray Observations of IceCube-260704A
  62. IceCube-260708A: Upper limits from a search for additional neutrino events in IceCube
  63. IceCube-260712A - IceCube observation of a high-energy neutrino candidate track-like event
  64. IceCube-260708A: Observations with the Vera C. Rubin Observatory
  65. IceCube-260708A: One candidate from the Zwicky Transient Facility
  66. IceCube Alert 260709A: Global MASTER-Net observations report
  67. IceCube-260708A - IceCube observation of a high-energy neutrino candidate track-like event
  68. IceCube-260704A: No candidates from the Zwicky Transient Facility
  69. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  70. IceCube260704A: OHP/T193 optical observations
  71. IceCube-260704A - IceCube observation of a high-energy neutrino candidate track-like event
  72. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  73. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  74. IceCube-260622A - IceCube observation of a high-energy neutrino candidate track-like event
  75. IceCube-Cascade 260618A: Upper limits from a search for additional neutrino events in IceCube
  76. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  77. IceCube-260610A: Upper limits from a search for additional neutrino events in IceCube
  78. IceCube-260610A: No candidates from the Zwicky Transient Facility
  79. IceCube-260610A: EP-FXT follow-up observation
  80. IceCube-260610A - IceCube observation of a high-energy neutrino candidate track-like event
  81. IceCube-260504A: No Candidate Transients from the Zwicky Transient Facility
  82. IceCube-260504A: Upper limits from a search for additional neutrino events in IceCube
  83. IceCube Alert 260505A: Global MASTER-Net observations report
  84. Fermi-LAT Gamma-ray Observations of IceCube-260504A
  85. IceCube-260504A - IceCube observation of a high-energy neutrino candidate track-like event
  86. IceCube-260425A: Upper limits from a search for additional neutrino events in IceCube
  87. Fermi-LAT Gamma-ray Observations of IceCube-260425A
  88. IceCube-260425A - IceCube observation of a high-energy neutrino candidate track-like event
  89. IceCube Alert 260425A: Global MASTER-Net observations report
  90. IceCube-Cascade 260418A: Upper limits from a search for additional neutrino events in IceCube
  91. EP260321a: Upper limits from a neutrino search with IceCube
  92. IceCube-260315A: No Candidate Transients from the Zwicky Transient Facility
  93. IceCube-260315A/AT2026fpm: EP-FXT follow-up observation
  94. Fermi-LAT Gamma-ray Observations of IceCube-260315A
  95. IceCube-260315A: Upper limits from a search for additional neutrino events in IceCube
  96. IceCube-260315A: COLIBRÍ optical observations
  97. IceCube Alert-260315A/AT2026fpm Automatic MASTER optical blue counterpart candidate
  98. IceCube-260315A - IceCube observation of a high-energy neutrino candidate track-like event
  99. IceCube Alert 260315A: Global MASTER-Net observations report
  100. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility

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