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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"
  1. GRB 220306B: Tautenburg observations
  2. GRB 220304A Fermi GBM detection
  3. IceCube-220306A: Upper limits from a search for additional neutrino events in IceCube
  4. IceCube-220304A: Upper limits from a search for additional neutrino events in IceCube
  5. GRB 220306B: Swift-BAT refined analysis
  6. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  7. GRB 220306B: AbAO optical observations, possible afterglow candidate
  8. GRB 220306B: BOOTES-1 optical upper limit
  9. GRB 220306B: Swift-XRT refined Analysis
  10. GRB 220306B: Fermi GBM observation
  11. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  12. GRB 220306B: Enhanced Swift-XRT position
  13. Swift GRB 220306B: Global MASTER-Net observations report
  14. GRB 220305A: Swift-BAT refined analysis
  15. GRB 220306B: Swift detection of a burst
  16. Fermi GBM Sub-Threshold Detection of GRB 220305A
  17. GRB 220305A: Swift-XRT refined Analysis
  18. Fermi GRB 220306A: Global MASTER-Net observations report
  19. GRB 220306A: Fermi GBM Final Real-time Localization
  20. IceCube-220306A - IceCube observation of a high-energy neutrino candidate track-like event
  21. Fermi GRB 220305A: Global MASTER-Net observations report
  22. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  23. GRB 220305A: Fermi GBM observation
  24. GRB 220305A: Enhanced Swift-XRT position
  25. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  26. Swift GRB 220305A: Global MASTER-Net observations report
  27. GRB 220305A: Swift-XRT observations
  28. GRB 220305A: Swift detection of a burst
  29. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  30. GRB 220302A: Swift/UVOT Upper Limits
  31. IceCube-220303A: Upper limits from a search for additional neutrino events in IceCube
  32. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  33. IceCube-220304A - IceCube observation of a high-energy neutrino candidate track-like event
  34. IceCube Alert 220304.74: Global MASTER-Net observations report
  35. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  36. Fermi GRB 220304A: Global MASTER-Net observations report
  37. Tev Blazar as possible optical counterpart of the high-energy neutrino IceCube-220303A
  38. GRB 220304A: BALROG localization (Fermi Trigger / GRB 220304228)
  39. GRB 220302A: Swift-XRT refined Analysis
  40. GRB 220304A: Fermi GBM Final Real-time Localization
  41. IceCube Alert 220303.75: Global MASTER-Net observations report
  42. IceCube-220303A - IceCube observation of a high-energy neutrino candidate track-like event
  43. GRB 220302A: BOOTES-5/JGT optical upper limit
  44. Swift resumes autonomous slewing
  45. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  46. GRB 220302A: Enhanced Swift-XRT position
  47. ZTF22aaajecp/AT2022cmc: ATCA detection
  48. GRB 220302A: Swift afterglow detection
  49. GRB 220222A: CALET Gamma-Ray Burst Monitor detection
  50. Swift GRB 220302A: Global MASTER-Net observations report
  51. GRB 220302A: Swift detection of a burst
  52. GRB 220228A: Fermi GBM observation
  53. GRB 220228A: Fermi-LAT detection
  54. GRB 220228A: Fermi GBM Final Localization
  55. Konus-Wind detection of GRB 220222A
  56. IceCube-220225A: Upper limits from a search for additional neutrino events in IceCube
  57. Fermi trigger No 667737010: Global MASTER-Net observations report
  58. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
  59. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  60. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  61. IceCube Alert 220225.59: Global MASTER-Net observations report
  62. IceCube-220225A - IceCube observation of a high-energy neutrino candidate track-like event
  63. IPN triangulation of GRB 220222A
  64. GRB 220101A: The first example of a Petanova
  65. ZTF22aaajecp/AT2022cmc: DECam Photometry
  66. Konus-Wind observation of GRB 220219B
  67. GCN Circ.draft on GRB 220222A
  68. GRB 220219B: Swift-XRT observations
  69. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  70. Fermi GRB 220223A: Global MASTER-Net observations report
  71. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  72. GRB 220223A: Fermi GBM Final Real-time Localization
  73. ZTF22aabjpxh/AT2022cva: 1.5m OSN optical observation
  74. IceCube-220221A: Upper limits from a search for additional neutrino events in IceCube
  75. Fermi GRB 220222B: Global MASTER-Net observations report
  76. GRB 220222B: Fermi GBM Final Real-time Localization
  77. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  78. GRB 220219B: Swift ToO observations
  79. GRB 220222A: Swift/BAT-GUANO detection outside the coded FOV
  80. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  81. Fermi GRB 220222A: Global MASTER-Net observations report
  82. GRB 220222A: Fermi GBM Final Real-time Localization
  83. ZTF22aabjpxh/AT2022cva: GMOS-N spectroscopy
  84. ZTF22aabjpxh/AT2022cva: Assy optical observations
  85. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  86. ZTF22aaajecb/AT 2022cmc: CAHA 2.2m/CAFOS detection, luminous transient
  87. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  88. IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
  89. IceCube Alert 220221.03: Global MASTER-Net observations report
  90. Konus-Wind observation of GRB 220219A
  91. IPN triangulation of GRB 220219A
  92. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  93. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  94. IceCube-220221A - IceCube observation of a high-energy neutrino candidate track-like event
  95. Fermi Gamma-ray Burst Monitor trigger 667074291/220220767 is not a GRB
  96. IceCube Alert 220220.60: Global MASTER-Net observations report
  97. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220220A
  98. Fermi trigger No 666962499: Global MASTER-Net observations report
  99. GRB 220218A: BOOTES-5/JGT optical upper limit
  100. ZTF22aaajecp/AT2022cmc: Keck DEIMOS Redshift

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