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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"

1520 results found.

  1. IceCube-230506A: IceCube observation of a high-energy neutrino candidate
  2. IceCube-Cascade 230430A: Upper limits from a search for additional neutrino events in IceCube
  3. IceCube-Cascade 230417A: Upper limits from a search for additional neutrino events in IceCube
  4. Fermi-LAT gamma-ray observations of IceCube-230416A
  5. Duplicate of GCN 33640
  6. Duplicate of GCN 33640
  7. IceCube-230416A: Upper limits from a search for additional neutrino events in IceCube
  8. IceCube-230416A: IceCube observation of a high-energy neutrino candidate
  9. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230414A
  10. IceCube-230405A: BOOTES-4/MET Optical Upper Limits
  11. IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
  12. Fermi-LAT gamma-ray observations of IceCube-230405A
  13. IceCube Alert 230405.56: Global MASTER-Net observations report
  14. IceCube-230405A: IceCube observation of a high-energy neutrino candidate
  15. Fermi-LAT gamma-ray observations of IceCube-230401A and detection of Fermi J0030.2+0005
  16. IceCube-230401A: Upper limits from a search for additional neutrino events in IceCube
  17. IceCube-230401A: IceCube observation of a high-energy neutrino candidate
  18. IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube
  19. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230313A
  20. GRB 230307A: ASO-S/HXI detection
  21. GRB 230307A: Upper limits from a neutrino search with IceCube
  22. IceCube-230306A: Upper limits from a search for additional neutrino events in IceCube
  23. Fermi-LAT gamma-ray observations of IceCube-230306A
  24. IceCube-230306A - IceCube observation of a high-energy neutrino candidate
  25. IceCube Alert 230306.46: Global MASTER-Net observations report
  26. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  27. Fermi-LAT gamma-ray observations of IceCube-230220A
  28. IceCube-230217A: Upper limits from a search for additional neutrino events in IceCube
  29. IceCube-230220A - IceCube observation of a high-energy neutrino candidate
  30. IceCube-230217A: BOOTES-4/MET Optical Observations
  31. Fermi-LAT gamma-ray observations of IceCube-230217A
  32. IceCube Alert 230217.87: Global MASTER-Net observations report
  33. IceCube-230217A - IceCube observation of a high-energy neutrino candidate track-like event
  34. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  35. IceCube-230201A: Upper limits from a search for additional neutrino events in IceCube
  36. IceCube Alert 230201.26: Global MASTER-Net observations report
  37. Fermi-LAT gamma-ray observations of IceCube-230201A
  38. IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
  39. IceCube-230122A: BOOTES-2/TELMA Optical Upper Limit
  40. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230125A
  41. IceCube-230122A: Upper limits from a search for additional neutrino events in IceCube
  42. Fermi-LAT gamma-ray observations of IceCube-230122A
  43. IceCube Alert 230122.16: Global MASTER-Net observations report
  44. IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
  45. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  46. Fermi-LAT gamma-ray observations of IceCube-230112A
  47. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  48. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  49. IceCube-230112A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube-230112A: BOOTES-4/MET Optical Upper Limit
  51. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  52. IceCube Alert 230112.28: Global MASTER-Net observations report
  53. IceCube-Cascade 230109A: Upper limits from a search for additional neutrino events in IceCube
  54. IceCube-221223A: JCMT/SCUBA2 observations
  55. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  56. Subject: IceCube-Cascade 221229A: Upper limits from a search for additional neutrino events in IceCube
  57. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  58. Fermi-LAT gamma-ray observations of IceCube-221229A
  59. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  60. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  61. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  62. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  63. Fermi-LAT gamma-ray observations of IceCube-221224A
  64. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  65. IceCube-221223A: BOOTES-4/MET Optical Observations
  66. Fermi-LAT gamma-ray observations of IceCube-221223A
  67. IceCube Alert 221224.04: Global MASTER-Net observations report
  68. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  69. IceCube Alert 221223.32: Global MASTER-Net observations report
  70. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  71. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  72. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  73. Fermi-LAT gamma-ray observations of IceCube-221216A
  74. IceCube-221216A: Upper limits from a search for additional neutrino events in IceCube
  75. Fermi-LAT gamma-ray observations of IceCube-221210A
  76. IceCube Alert 221216.25: Global MASTER-Net observations report
  77. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  78. IceCube-221210A: Upper limits from a search for additional neutrino events in IceCube
  79. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  80. IceCube Alert 221210.36: Global MASTER-Net observations report
  81. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  82. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  83. Fermi-LAT gamma-ray observations of IceCube-221124A
  84. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  85. IceCube Alert 221124.66: Global MASTER-Net observations report
  86. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  87. IceCube Alert 221104.26: Global MASTER-Net observations report
  88. Fermi-LAT gamma-ray observations of IceCube-221104A
  89. IceCube-221104A - IceCube observation of a high-energy neutrino candidate track-like event
  90. GRB 221009A: MITSuME Okayama optical observation
  91. GRB 221009A: Upper limits from a neutrino search with IceCube
  92. Fermi-LAT gamma-ray observations of IceCube-220928A
  93. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  94. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  95. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  96. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  97. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  98. IceCube Alert 220918.53: Global MASTER-Net observations report
  99. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  100. IceCube-220907A: No significant detection in HAWC

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Download all Circulars as a .tar.gz archive (updated once a day):
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