Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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-220421A: Upper limits from a search for additional neutrino events in IceCube
  2. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  3. IceCube-220425A: MASTER: flaring blazar TXS 1742-078 as the possible neutrino source candidate
  4. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  5. IceCube Alert 220425.11: Global MASTER-Net observations report
  6. IceCube-220425A - IceCube observation of a high-energy neutrino candidate track-like event
  7. IceCube-220424A - IceCube observation of a high-energy neutrino candidate track-like event
  8. IceCube Alert 220424.05: Global MASTER-Net observations report
  9. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  10. IceCube-220421A - IceCube observation of a high-energy neutrino candidate track-like event
  11. IceCube Alert 220421.22: Global MASTER-Net observations report
  12. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  13. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  14. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  15. IceCube Alert 220405.93: Global MASTER-Net observations report
  16. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  17. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  18. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  19. IceCube Alert 220405.21: Global MASTER-Net observations report
  20. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  21. IceCube-220317A: Upper limits from a search for additional neutrino events in IceCube
  22. IceCube-220317A: MASTER Global Robotic Net optical observations
  23. IceCube-220317A - IceCube observation of a high-energy neutrino candidate track-like event
  24. IceCube-220306A: No significant detection in HAWC
  25. IceCube-220303A: No significant detection in HAWC
  26. IceCube-220306A: Upper limits from a search for additional neutrino events in IceCube
  27. IceCube-220304A: Upper limits from a search for additional neutrino events in IceCube
  28. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  29. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  30. IceCube-220306A - IceCube observation of a high-energy neutrino candidate track-like event
  31. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  32. IceCube-220303A: Upper limits from a search for additional neutrino events in IceCube
  33. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  34. IceCube-220304A - IceCube observation of a high-energy neutrino candidate track-like event
  35. IceCube Alert 220304.74: Global MASTER-Net observations report
  36. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  37. IceCube Alert 220303.75: Global MASTER-Net observations report
  38. IceCube-220303A - IceCube observation of a high-energy neutrino candidate track-like event
  39. IceCube-220225A: Upper limits from a search for additional neutrino events in IceCube
  40. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  41. IceCube Alert 220225.59: Global MASTER-Net observations report
  42. IceCube-220225A - IceCube observation of a high-energy neutrino candidate track-like event
  43. IceCube-220221A: Upper limits from a search for additional neutrino events in IceCube
  44. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  45. IceCube Alert 220221.03: Global MASTER-Net observations report
  46. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  47. IceCube-220221A - IceCube observation of a high-energy neutrino candidate track-like event
  48. IceCube Alert 220220.60: Global MASTER-Net observations report
  49. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220220A
  50. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220212A
  51. IceCube-220205B: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-220205A: Upper limits from a search for additional neutrino events in IceCube
  53. Fermi-LAT Gamma-ray Observations of IceCube-220205B
  54. Fermi-LAT Gamma-ray Observations of IceCube-220205A
  55. IceCube-220205B: No neutrino counterpart candidates in ANTARES search
  56. IceCube-220205B - IceCube observation of a high-energy neutrino candidate track-like event
  57. IceCube-220205A - IceCube observation of a high-energy neutrino candidate track-like event
  58. Fermi-LAT Gamma-ray Observations of IceCube-220202A
  59. IceCube-220202A: Upper limits from a search for additional neutrino events in IceCube
  60. IceCube-220202A: IceCube observation of a high-energy neutrino candidate track-like event
  61. IceCube Alert 220202.49: Global MASTER-Net observations report
  62. IceCube-211208A: the optical observation of the candidate PKS0735+178
  63. Fermi-LAT-ANTARES 220121a: upper limits from a search for coincident neutrinos with IceCube
  64. IceCube-220115A: Upper limits from a search for additional neutrino events in IceCube
  65. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
  66. IceCube Alert 220115.51: Global MASTER-Net observations report
  67. IceCube-220115A - IceCube observation of a high-energy neutrino candidate track-like event
  68. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  69. IceCube-211216B: No significant detection in HAWC
  70. IceCube-211216A: No significant detection in HAWC
  71. IceCube-211216B: No neutrino counterpart candidates in ANTARES search
  72. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  73. Fermi-LAT Gamma-ray Observations of IceCube-211216A
  74. IceCube-211216B: Upper limits from Fermi-GBM Observations
  75. IceCube-211216A: Upper limits from Fermi-GBM Observations
  76. IceCube-211216A: Upper limits from a search for additional neutrino events in IceCube
  77. IceCube-211216A: No neutrino counterpart candidates in ANTARES search
  78. IceCube-211216B - IceCube observation of a high-energy neutrino candidate track-like event
  79. IceCube Alert 211216.99: Global MASTER-Net observations report
  80. IceCube Alert 211216.30: Global MASTER-Net observations report
  81. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. IceCube-211216A - IceCube observation of a high-energy neutrino candidate track-like event
  83. IceCube-211208A: No neutrino counterpart detected with ANTARES
  84. IceCube-211208A: No significant detection in HAWC
  85. IceCube-211208A: Upper limits from a search for additional neutrino events in IceCube
  86. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  87. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  88. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-211209A
  89. IceCube-211208A - IceCube observation of a high-energy neutrino candidate track-like event
  90. IceCube Alert 211208.84: Global MASTER-Net observations report
  91. IceCube-211125A: No significant detection in HAWC
  92. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  93. IceCube-211125A: Upper limits from a search for additional neutrino events in IceCube
  94. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  95. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  96. IceCube-211125A: No neutrino counterpart detected with ANTARES
  97. IceCube-211125A: IceCube observation of a high-energy neutrino candidate track-like event
  98. IceCube Alert 211125.27: Global MASTER-Net observations report
  99. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  100. IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov