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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-211123A: INTEGRAL was inactive at the time of the event
  2. IceCube-211123A: Upper limits from Fermi-GBM Observations
  3. IceCube-211117A: not observable by Fermi-GBM
  4. IceCube-211116A: not observable by Fermi-GBM
  5. IceCube-211023A: not observable by Fermi-GBM
  6. IceCube Alert 211123.60: Global MASTER-Net observations report
  7. IceCube-211123A - IceCube observation of a high-energy neutrino candidate track-like event
  8. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  9. Search for counterpart to IceCube-211117A with ANTARES
  10. IceCube-211117A : IceCube observation of a high-energy neutrino candidate track-like event
  11. IceCube-211116A: Upper limits from a search for additional neutrino events in IceCube
  12. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  13. IceCube-211116A: No neutrino counterpart detected with ANTARES
  14. IceCube Alert 211116.44: Global MASTER-Net observations report
  15. IceCube-211116A : IceCube observation of a high-energy neutrino candidate track-like event
  16. IceCube-211023A: Upper limits from a search for additional neutrino events in IceCube
  17. Fermi-LAT Gamma-ray Observations of IceCube-211023A
  18. IceCube-211023A: No neutrino counterpart detected with ANTARES
  19. IceCube Alert 211023.36: Global MASTER-Net observations report
  20. IceCube-211023A - IceCube observation of a high-energy neutrino candidate track-like event
  21. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-211020A
  22. IceCube-210922A: Hard X-ray flux limit for JCMT/SCUBA2 source from NuSTAR observations
  23. IceCube-20210922A: No optical counterparts found by MITSuME observations
  24. IceCube-20210922A: DESNU Optical counterpart candidate from 5 nights of DECam observations
  25. IceCube-210922A: DESI Observations
  26. Fermi-LAT Gamma-ray Observations of IceCubeCascade-210926A
  27. IceCube-210922A: SMA observation for the JCMT candidate
  28. IceCube-210926A: No neutrino counterpart candidates in ANTARES search
  29. IceCube-210922A: JCMT/SCUBA2 observations
  30. IceCube-210922A: No Candidate Counterparts from Swift/XRT follow up observations
  31. IceCube-210922A: No significant detection in HAWC
  32. IceCube-210922A: No neutrino counterpart candidates in ANTARES search
  33. IceCube-210922A: Upper limits from a search for additional neutrino events in IceCube
  34. IceCube-210922A: Upper limits from Fermi-GBM Observations
  35. IceCube-210922A: No Candidate Counterparts from the Zwicky Transient Facility
  36. Fermi-LAT Gamma-ray Observations of IceCube-210922A
  37. IceCube Alert 210922.76: Global MASTER-Net observations report
  38. IceCube-210922A - IceCube observation of a high-energy neutrino candidate track-like event
  39. IceCube-210811A: Upper limits from a search for additional neutrino events in IceCube
  40. IceCube-210730A: not observable by Fermi-GBM
  41. IceCube-210811A: Upper limits from Fermi-GBM Observations
  42. IceCube-210811A: No Candidate Counterparts from the Zwicky Transient Facility
  43. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  44. IceCube-210811A - IceCube observation of a high-energy neutrino candidate track-like event
  45. IceCube Alert 210811.09: Global MASTER-Net observations report
  46. IceCube-210730A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  47. Fermi-LAT Gamma-ray Observations of IceCube-210730A
  48. IceCube-210730A - IceCube observation of a high-energy neutrino candidate track-like event
  49. Fermi-LAT Gamma-ray Observations of IceCube-210717A
  50. IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  51. IceCube-210717A: IceCube observation of a high-energy neutrino candidate track-like event
  52. IceCube-210629A - Spectroscopic observation of AT2021osi
  53. IceCube-210516A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  54. IceCube-210510A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  55. IceCube-210629A: Upper limits from a search for additional neutrino events in IceCube
  56. IceCube-210629A: One Candidate Counterpart from the Zwicky Transient Facility
  57. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  58. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  59. IceCube-210629A: Upper limits from Fermi-GBM Observations
  60. IceCube Alert 210629.76: Global MASTER-Net observations report
  61. IceCube-210629A - IceCube observation of a high-energy neutrino candidate track-like event
  62. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  63. IceCube-210608A: not observable by Fermi-GBM
  64. IceCube-210608A: IceCube observation of a high-energy neutrino candidate track-like event
  65. IceCube Alert 210608.15: Global MASTER-Net observations report
  66. IceCube GCN alert 135302_36915486.amon retraction
  67. IceCube Alert 210519.86: Global MASTER-Net observations report
  68. Fermi-LAT Gamma-ray Observations of IceCube-210516A
  69. IceCube Alert 210515.01: Global MASTER-Net observations report
  70. IceCube-210516A: No significant detection in HAWC
  71. IceCube-210516A: Upper limits from a search for additional neutrino events in IceCube
  72. IceCube Alert 210516.61: Global MASTER-Net observations report
  73. IceCube-210516A - IceCube observation of a high-energy neutrino candidate track-like event
  74. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEM-210515A and 210515B
  75. IceCube-210510A: Upper limits from a search for additional neutrino events in IceCube
  76. IceCube-210510A: not observable by Fermi-GBM
  77. IceCube-210510A: No candidate counterparts from the Zwicky Transient Facility
  78. Fermi-LAT Gamma-ray Observations of IceCube-210510A
  79. IceCube Alert 210510.20: Global MASTER-Net observations report
  80. IceCube-210510A: DDOTI Upper Limits
  81. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  82. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  83. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  84. IceCube Alert 210416.09: Global MASTER-Net observations report
  85. IceCubeCascade-210416a: Kanata Optical Imaging of 3C 279
  86. IceCube Alert 210322.11: Global MASTER-Net observations report
  87. IceCube 135113_19489408.amon: Swift-XRT observations
  88. IceCube Astrotrack Bronze 135113_19489408.amon is likely background
  89. IceCube-210210A: Two Additional Optical Candidate Counterparts Found by DECam
  90. IceCube alert 134994_1103075 retraction
  91. IceCube Alert 210213.78: Global MASTER-Net observations report
  92. IceCube-210210A: Four Candidate Optical Counterparts from DECam Observations
  93. IceCube-210210A: Upper limits from a search for additional neutrino events in IceCube
  94. Swift-XRT observations of IceCube-210210A
  95. IceCube-210210A: No neutrino counterpart in ANTARES
  96. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  97. IceCube Alert 210210.50: Global MASTER-Net observations report
  98. IceCube-210210A: Upper limits from Fermi-GBM Observations
  99. IceCube-210210A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  100. IceCube-210210A: Two Candidate Counterparts from the Zwicky Transient Facility

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