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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"

1462 results found.

  1. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  2. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  3. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  4. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  5. Fermi-LAT gamma-ray observations of IceCube-221224A
  6. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  7. IceCube-221223A: BOOTES-4/MET Optical Observations
  8. Fermi-LAT gamma-ray observations of IceCube-221223A
  9. IceCube Alert 221224.04: Global MASTER-Net observations report
  10. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  11. IceCube Alert 221223.32: Global MASTER-Net observations report
  12. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  13. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  14. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  15. Fermi-LAT gamma-ray observations of IceCube-221216A
  16. IceCube-221216A: Upper limits from a search for additional neutrino events in IceCube
  17. Fermi-LAT gamma-ray observations of IceCube-221210A
  18. IceCube Alert 221216.25: Global MASTER-Net observations report
  19. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  20. IceCube-221210A: Upper limits from a search for additional neutrino events in IceCube
  21. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  22. IceCube Alert 221210.36: Global MASTER-Net observations report
  23. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  24. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  25. Fermi-LAT gamma-ray observations of IceCube-221124A
  26. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  27. IceCube Alert 221124.66: Global MASTER-Net observations report
  28. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  29. IceCube Alert 221104.26: Global MASTER-Net observations report
  30. Fermi-LAT gamma-ray observations of IceCube-221104A
  31. IceCube-221104A - IceCube observation of a high-energy neutrino candidate track-like event
  32. GRB 221009A: MITSuME Okayama optical observation
  33. GRB 221009A: Upper limits from a neutrino search with IceCube
  34. Fermi-LAT gamma-ray observations of IceCube-220928A
  35. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  36. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  37. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  38. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  39. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  40. IceCube Alert 220918.53: Global MASTER-Net observations report
  41. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  42. IceCube-220907A: No significant detection in HAWC
  43. IceCube-220907A: Upper limits from a search for additional neutrino events in IceCube
  44. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  45. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  46. IceCube-220907A - IceCube observation of a high-energy neutrino candidate track-like event
  47. IceCube Alert 220907.28: Global MASTER-Net observations report
  48. IceCube-220822A: No significant detection in HAWC
  49. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  51. IceCube-220822A: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  53. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  54. IceCube-220822A - IceCube observation of a high-energy neutrino candidate track-like event
  55. IceCube Alert 220822.85: Global MASTER-Net observations report
  56. IceCube Astrotrack Bronze 136918_45252263.amon is likely background
  57. IceCube Alert 220808.33: Global MASTER-Net observations report
  58. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  59. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  60. IceCube-220629A: Upper limits from a search for additional neutrino events in IceCube
  61. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  62. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  63. IceCube-220629A: No significant detection in HAWC
  64. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  65. IceCube-220627A: No significant detection in HAWC
  66. IceCube Alert 220629.99: Global MASTER-Net observations report
  67. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  68. IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
  69. Swift XRT observations of WISEA J145820.77+412101.9 / IceCube 220624A
  70. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  71. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-220627A - IceCube observation of a high-energy neutrino candidate track-like event
  73. IceCube Alert 220627.74: Global MASTER-Net observations report
  74. IceCube-220624A: Upper limits from a search for additional neutrino events in IceCube
  75. IceCube-220624A: No significant detection in HAWC
  76. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  77. IceCube Alert 220624.68: Global MASTER-Net observations report
  78. IceCube-220624A - IceCube observation of a high-energy neutrino candidate track-like event
  79. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  80. IceCube-220524A: Upper limits from a search for additional neutrino events in IceCube
  81. IceCube-220524A - IceCube observation of a high-energy neutrino candidate track-like event
  82. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  83. IceCube-220513A: Upper limits from a search for additional neutrino events in IceCube
  84. IceCube-220513A: No significant detection in HAWC
  85. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  86. IceCube-220513A - IceCube observation of a high-energy neutrino candidate track-like event
  87. IceCube Alert 220513.97: Global MASTER-Net observations report
  88. IceCube-220509A: No significant detection in HAWC
  89. IceCube-220509A: Upper limits from a search for additional neutrino events in IceCube
  90. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  91. IceCube-220509A - IceCube observation of a high-energy neutrino candidate track-like event
  92. IceCube Alert 220509.76: Global MASTER-Net observations report
  93. IceCube-220405B - ZTF19aavnpjv unrelated
  94. IceCube-220501A: Upper limits from a search for additional neutrino events in IceCube
  95. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  96. IceCube-220501A: No Candidate Counterparts from the Zwicky Transient Facility
  97. IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
  98. IceCube Alert 220501.95: Global MASTER-Net observations report
  99. IceCube-220425A: Upper limits from a search for additional neutrino events in IceCube
  100. IceCube-220424A: Upper limits from a search for additional neutrino events in IceCube

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