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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-230416A: IceCube observation of a high-energy neutrino candidate
  2. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
  3. IceCube-230405A: BOOTES-4/MET Optical Upper Limits
  4. IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
  5. Fermi-LAT gamma-ray observations of IceCube-230405A
  6. IceCube Alert 230405.56: Global MASTER-Net observations report
  7. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  8. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  9. IceCube-230401A: Upper limits from a search for additional neutrino events in IceCube
  10. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  11. IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube
  12. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230313A
  13. GRB 230307A: ASO-S/HXI detection
  14. GRB 230307A: Upper limits from a neutrino search with IceCube
  15. IceCube-230306A: Upper limits from a search for additional neutrino events in IceCube
  16. Fermi-LAT gamma-ray observations of IceCube-230306A
  17. IceCube-230306A - IceCube observation of a high-energy neutrino candidate
  18. IceCube Alert 230306.46: Global MASTER-Net observations report
  19. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  20. Fermi-LAT gamma-ray observations of IceCube-230220A
  21. IceCube-230217A: Upper limits from a search for additional neutrino events in IceCube
  22. IceCube-230220A - IceCube observation of a high-energy neutrino candidate
  23. IceCube-230217A: BOOTES-4/MET Optical Observations
  24. Fermi-LAT gamma-ray observations of IceCube-230217A
  25. IceCube Alert 230217.87: Global MASTER-Net observations report
  26. IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event
  27. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  28. IceCube-230201A: Upper limits from a search for additional neutrino events in IceCube
  29. IceCube Alert 230201.26: Global MASTER-Net observations report
  30. Fermi-LAT gamma-ray observations of IceCube-230201A
  31. IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
  32. IceCube-230122A: BOOTES-2/TELMA Optical Upper Limit
  33. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230125A
  34. IceCube-230122A: Upper limits from a search for additional neutrino events in IceCube
  35. Fermi-LAT gamma-ray observations of IceCube-230122A
  36. IceCube Alert 230122.16: Global MASTER-Net observations report
  37. IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
  38. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  39. Fermi-LAT gamma-ray observations of IceCube-230112A
  40. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  41. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  42. IceCube-230112A: Upper limits from a search for additional neutrino events in IceCube
  43. IceCube-230112A: BOOTES-4/MET Optical Upper Limit
  44. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  45. IceCube Alert 230112.28: Global MASTER-Net observations report
  46. IceCube-Cascade 230109A: Upper limits from a search for additional neutrino events in IceCube
  47. IceCube-221223A: JCMT/SCUBA2 observations
  48. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  49. Subject: IceCube-Cascade 221229A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  51. Fermi-LAT gamma-ray observations of IceCube-221229A
  52. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  53. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  54. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  55. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  56. Fermi-LAT gamma-ray observations of IceCube-221224A
  57. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  58. IceCube-221223A: BOOTES-4/MET Optical Observations
  59. Fermi-LAT gamma-ray observations of IceCube-221223A
  60. IceCube Alert 221224.04: Global MASTER-Net observations report
  61. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  62. IceCube Alert 221223.32: Global MASTER-Net observations report
  63. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  64. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  65. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  66. Fermi-LAT gamma-ray observations of IceCube-221216A
  67. IceCube-221216A: Upper limits from a search for additional neutrino events in IceCube
  68. Fermi-LAT gamma-ray observations of IceCube-221210A
  69. IceCube Alert 221216.25: Global MASTER-Net observations report
  70. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  71. IceCube-221210A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  73. IceCube Alert 221210.36: Global MASTER-Net observations report
  74. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  75. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  76. Fermi-LAT gamma-ray observations of IceCube-221124A
  77. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  78. IceCube Alert 221124.66: Global MASTER-Net observations report
  79. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  80. IceCube Alert 221104.26: Global MASTER-Net observations report
  81. Fermi-LAT gamma-ray observations of IceCube-221104A
  82. IceCube-221104A - IceCube observation of a high-energy neutrino candidate track-like event
  83. GRB 221009A: MITSuME Okayama optical observation
  84. GRB 221009A: Upper limits from a neutrino search with IceCube
  85. Fermi-LAT gamma-ray observations of IceCube-220928A
  86. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  87. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  88. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  89. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  90. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  91. IceCube Alert 220918.53: Global MASTER-Net observations report
  92. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  93. IceCube-220907A: No significant detection in HAWC
  94. IceCube-220907A: Upper limits from a search for additional neutrino events in IceCube
  95. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  96. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  97. IceCube-220907A - IceCube observation of a high-energy neutrino candidate track-like event
  98. IceCube Alert 220907.28: Global MASTER-Net observations report
  99. IceCube-220822A: No significant detection in HAWC
  100. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube

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