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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"

1360 results found.

  1. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  2. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  3. Fermi-LAT gamma-ray observations of IceCube-221224A
  4. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  5. IceCube-221223A: BOOTES-4/MET Optical Observations
  6. Fermi-LAT gamma-ray observations of IceCube-221223A
  7. IceCube Alert 221224.04: Global MASTER-Net observations report
  8. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  9. IceCube Alert 221223.32: Global MASTER-Net observations report
  10. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  11. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  12. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  13. Fermi-LAT gamma-ray observations of IceCube-221216A
  14. IceCube-221216A: Upper limits from a search for additional neutrino events in IceCube
  15. Fermi-LAT gamma-ray observations of IceCube-221210A
  16. IceCube Alert 221216.25: Global MASTER-Net observations report
  17. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  18. IceCube-221210A: Upper limits from a search for additional neutrino events in IceCube
  19. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  20. IceCube Alert 221210.36: Global MASTER-Net observations report
  21. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  22. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  23. Fermi-LAT gamma-ray observations of IceCube-221124A
  24. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  25. IceCube Alert 221124.66: Global MASTER-Net observations report
  26. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  27. IceCube Alert 221104.26: Global MASTER-Net observations report
  28. Fermi-LAT gamma-ray observations of IceCube-221104A
  29. IceCube-221104A - IceCube observation of a high-energy neutrino candidate track-like event
  30. GRB 221009A: MITSuME Okayama optical observation
  31. GRB 221009A: Upper limits from a neutrino search with IceCube
  32. Fermi-LAT gamma-ray observations of IceCube-220928A
  33. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  34. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  35. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  36. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  37. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  38. IceCube Alert 220918.53: Global MASTER-Net observations report
  39. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  40. IceCube-220907A: No significant detection in HAWC
  41. IceCube-220907A: Upper limits from a search for additional neutrino events in IceCube
  42. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  43. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  44. IceCube-220907A - IceCube observation of a high-energy neutrino candidate track-like event
  45. IceCube Alert 220907.28: Global MASTER-Net observations report
  46. IceCube-220822A: No significant detection in HAWC
  47. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube
  48. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  49. IceCube-220822A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  51. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  52. IceCube-220822A - IceCube observation of a high-energy neutrino candidate track-like event
  53. IceCube Alert 220822.85: Global MASTER-Net observations report
  54. IceCube Astrotrack Bronze 136918_45252263.amon is likely background
  55. IceCube Alert 220808.33: Global MASTER-Net observations report
  56. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  57. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  58. IceCube-220629A: Upper limits from a search for additional neutrino events in IceCube
  59. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  60. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  61. IceCube-220629A: No significant detection in HAWC
  62. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  63. IceCube-220627A: No significant detection in HAWC
  64. IceCube Alert 220629.99: Global MASTER-Net observations report
  65. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  66. IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
  67. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  68. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  69. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  70. IceCube-220627A - IceCube observation of a high-energy neutrino candidate track-like event
  71. IceCube Alert 220627.74: Global MASTER-Net observations report
  72. IceCube-220624A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-220624A: No significant detection in HAWC
  74. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  75. IceCube Alert 220624.68: Global MASTER-Net observations report
  76. IceCube-220624A - IceCube observation of a high-energy neutrino candidate track-like event
  77. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  78. IceCube-220524A: Upper limits from a search for additional neutrino events in IceCube
  79. IceCube-220524A - IceCube observation of a high-energy neutrino candidate track-like event
  80. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  81. IceCube-220513A: Upper limits from a search for additional neutrino events in IceCube
  82. IceCube-220513A: No significant detection in HAWC
  83. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  84. IceCube-220513A - IceCube observation of a high-energy neutrino candidate track-like event
  85. IceCube Alert 220513.97: Global MASTER-Net observations report
  86. IceCube-220509A: No significant detection in HAWC
  87. IceCube-220509A: Upper limits from a search for additional neutrino events in IceCube
  88. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  89. IceCube-220509A - IceCube observation of a high-energy neutrino candidate track-like event
  90. IceCube Alert 220509.76: Global MASTER-Net observations report
  91. IceCube-220405B - ZTF19aavnpjv unrelated
  92. IceCube-220501A: Upper limits from a search for additional neutrino events in IceCube
  93. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  94. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  95. IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
  96. IceCube Alert 220501.95: Global MASTER-Net observations report
  97. IceCube-220425A: Upper limits from a search for additional neutrino events in IceCube
  98. IceCube-220424A: Upper limits from a search for additional neutrino events in IceCube
  99. IceCube-220421A: Upper limits from a search for additional neutrino events in IceCube
  100. Fermi-LAT Gamma-ray Observations of IceCube-220425A

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