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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"

1413 results found.

  1. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  2. IceCube-220822A: Upper limits from a search for additional neutrino events in IceCube
  3. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  4. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  5. IceCube-220822A - IceCube observation of a high-energy neutrino candidate track-like event
  6. IceCube Alert 220822.85: Global MASTER-Net observations report
  7. IceCube Astrotrack Bronze 136918_45252263.amon is likely background
  8. IceCube Alert 220808.33: Global MASTER-Net observations report
  9. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  10. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  11. IceCube-220629A: Upper limits from a search for additional neutrino events in IceCube
  12. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  13. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  14. IceCube-220629A: No significant detection in HAWC
  15. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  16. IceCube-220627A: No significant detection in HAWC
  17. IceCube Alert 220629.99: Global MASTER-Net observations report
  18. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  19. IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
  20. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  21. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  22. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  23. IceCube-220627A - IceCube observation of a high-energy neutrino candidate track-like event
  24. IceCube Alert 220627.74: Global MASTER-Net observations report
  25. IceCube-220624A: Upper limits from a search for additional neutrino events in IceCube
  26. IceCube-220624A: No significant detection in HAWC
  27. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  28. IceCube Alert 220624.68: Global MASTER-Net observations report
  29. IceCube-220624A - IceCube observation of a high-energy neutrino candidate track-like event
  30. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  31. IceCube-220524A: Upper limits from a search for additional neutrino events in IceCube
  32. IceCube-220524A - IceCube observation of a high-energy neutrino candidate track-like event
  33. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  34. IceCube-220513A: Upper limits from a search for additional neutrino events in IceCube
  35. IceCube-220513A: No significant detection in HAWC
  36. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  37. IceCube-220513A - IceCube observation of a high-energy neutrino candidate track-like event
  38. IceCube Alert 220513.97: Global MASTER-Net observations report
  39. IceCube-220509A: No significant detection in HAWC
  40. IceCube-220509A: Upper limits from a search for additional neutrino events in IceCube
  41. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  42. IceCube-220509A - IceCube observation of a high-energy neutrino candidate track-like event
  43. IceCube Alert 220509.76: Global MASTER-Net observations report
  44. IceCube-220405B - ZTF19aavnpjv unrelated
  45. IceCube-220501A: Upper limits from a search for additional neutrino events in IceCube
  46. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  47. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  48. IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
  49. IceCube Alert 220501.95: Global MASTER-Net observations report
  50. IceCube-220425A: Upper limits from a search for additional neutrino events in IceCube
  51. IceCube-220424A: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-220421A: Upper limits from a search for additional neutrino events in IceCube
  53. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  54. IceCube-220425A: MASTER: flaring blazar TXS 1742-078 as the possible neutrino source candidate
  55. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  56. IceCube Alert 220425.11: Global MASTER-Net observations report
  57. IceCube-220425A - IceCube observation of a high-energy neutrino candidate track-like event
  58. IceCube-220424A - IceCube observation of a high-energy neutrino candidate track-like event
  59. IceCube Alert 220424.05: Global MASTER-Net observations report
  60. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  61. IceCube-220421A - IceCube observation of a high-energy neutrino candidate track-like event
  62. IceCube Alert 220421.22: Global MASTER-Net observations report
  63. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  64. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  65. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  66. IceCube Alert 220405.93: Global MASTER-Net observations report
  67. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  68. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  69. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  70. IceCube Alert 220405.21: Global MASTER-Net observations report
  71. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  72. IceCube-220317A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-220317A: MASTER Global Robotic Net optical observations
  74. IceCube-220317A - IceCube observation of a high-energy neutrino candidate track-like event
  75. IceCube-220306A: No significant detection in HAWC
  76. IceCube-220303A: No significant detection in HAWC
  77. IceCube-220306A: Upper limits from a search for additional neutrino events in IceCube
  78. IceCube-220304A: Upper limits from a search for additional neutrino events in IceCube
  79. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  80. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  81. IceCube-220306A - IceCube observation of a high-energy neutrino candidate track-like event
  82. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  83. IceCube-220303A: Upper limits from a search for additional neutrino events in IceCube
  84. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  85. IceCube-220304A - IceCube observation of a high-energy neutrino candidate track-like event
  86. IceCube Alert 220304.74: Global MASTER-Net observations report
  87. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  88. IceCube Alert 220303.75: Global MASTER-Net observations report
  89. IceCube-220303A - IceCube observation of a high-energy neutrino candidate track-like event
  90. IceCube-220225A: Upper limits from a search for additional neutrino events in IceCube
  91. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  92. IceCube Alert 220225.59: Global MASTER-Net observations report
  93. IceCube-220225A - IceCube observation of a high-energy neutrino candidate track-like event
  94. IceCube-220221A: Upper limits from a search for additional neutrino events in IceCube
  95. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  96. IceCube Alert 220221.03: Global MASTER-Net observations report
  97. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  98. IceCube-220221A - IceCube observation of a high-energy neutrino candidate track-like event
  99. IceCube Alert 220220.60: Global MASTER-Net observations report
  100. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220220A

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