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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"

34119 results found.

  1. IPN triangulation of GRB 220308A (long / very bright)
  2. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  3. IPN triangulation of GRB 220305B
  4. GRB 220306B: Tautenburg observations
  5. GRB 220304A Fermi GBM detection
  6. GRB 220306B: Swift-BAT refined analysis
  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. GRB 220306B: Enhanced Swift-XRT position
  12. Swift GRB 220306B: Global MASTER-Net observations report
  13. GRB 220305A: Swift-BAT refined analysis
  14. GRB 220306B: Swift detection of a burst
  15. Fermi GBM Sub-Threshold Detection of GRB 220305A
  16. GRB 220305A: Swift-XRT refined Analysis
  17. Fermi GRB 220306A: Global MASTER-Net observations report
  18. GRB 220306A: Fermi GBM Final Real-time Localization
  19. Fermi GRB 220305A: Global MASTER-Net observations report
  20. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  21. GRB 220305A: Fermi GBM observation
  22. GRB 220305A: Enhanced Swift-XRT position
  23. Swift GRB 220305A: Global MASTER-Net observations report
  24. GRB 220305A: Swift-XRT observations
  25. GRB 220305A: Swift detection of a burst
  26. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  27. GRB 220302A: Swift/UVOT Upper Limits
  28. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  29. Fermi GRB 220304A: Global MASTER-Net observations report
  30. GRB 220304A: BALROG localization (Fermi Trigger / GRB 220304228)
  31. GRB 220302A: Swift-XRT refined Analysis
  32. GRB 220304A: Fermi GBM Final Real-time Localization
  33. GRB 220302A: BOOTES-5/JGT optical upper limit
  34. GRB 220302A: Enhanced Swift-XRT position
  35. GRB 220302A: Swift afterglow detection
  36. GRB 220222A: CALET Gamma-Ray Burst Monitor detection
  37. Swift GRB 220302A: Global MASTER-Net observations report
  38. GRB 220302A: Swift detection of a burst
  39. GRB 220228A: Fermi GBM observation
  40. GRB 220228A: Fermi-LAT detection
  41. GRB 220228A: Fermi GBM Final Localization
  42. Konus-Wind detection of GRB 220222A
  43. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  44. IPN triangulation of GRB 220222A
  45. GRB 220101A: The first example of a Petanova
  46. Konus-Wind observation of GRB 220219B
  47. GCN Circ.draft on GRB 220222A
  48. GRB 220219B: Swift-XRT observations
  49. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  50. Fermi GRB 220223A: Global MASTER-Net observations report
  51. GRB 220223A: Fermi GBM Final Real-time Localization
  52. Fermi GRB 220222B: Global MASTER-Net observations report
  53. GRB 220222B: Fermi GBM Final Real-time Localization
  54. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  55. GRB 220219B: Swift ToO observations
  56. GRB 220222A: Swift/BAT-GUANO detection outside the coded FOV
  57. Fermi GRB 220222A: Global MASTER-Net observations report
  58. GRB 220222A: Fermi GBM Final Real-time Localization
  59. ZTF22aabjpxh/AT2022cva: Assy optical observations
  60. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  61. ZTF22aaajecb/AT 2022cmc: CAHA 2.2m/CAFOS detection, luminous transient
  62. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  63. IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
  64. Konus-Wind observation of GRB 220219A
  65. IPN triangulation of GRB 220219A
  66. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  67. Fermi Gamma-ray Burst Monitor trigger 667074291/220220767 is not a GRB
  68. GRB 220218A: BOOTES-5/JGT optical upper limit
  69. GRB 220219A: AGILE/MCAL detection
  70. GRB 220219A: BALROG localization (Fermi Trigger / GRB 220219473)
  71. GRB 220219A: Fermi GBM Final Real-time Localization
  72. GRB 220218A: Swift detection of a burst
  73. GRB 220211A: redshift lower limit estimating
  74. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  75. Konus-Wind detection of GRB 220209A
  76. GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc
  77. Konus-Wind detection of GRB 220211A
  78. IPN triangulation of GRB 220209A
  79. GRB 211023A: evidence of supernova in LBT spectra
  80. ZTF22aaajecp/AT2022cmc: Liverpool Telescope photometry
  81. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  82. ZTF22aaajecp/AT2022cmc: VLA radio detection
  83. GRB 220211A: Fermi GBM observation
  84. ZTF22aaajecp/AT2022cmc: Zwicky Transient Facility discovery of a fast and red optical transient
  85. GRB 220214A: Fermi GBM Final Real-time Localization
  86. Fermi GBM trigger 666393834/220212892 is not a GRB
  87. GRB 220210A: Mondy, AbAO and Terskol optical upper limits
  88. IPN triangulation of GRB 220211A (short)
  89. GRB 220210A: Insight-HXMT/HE detection
  90. GRB 220211A: Swift/BAT-GUANO detection outside the coded FOV (short)
  91. GRB 220210A: 1.5m OSN optical upper limit
  92. GRB 220210A: Fermi GBM detection
  93. Fermi GRB 220211B: Global MASTER-Net observations report
  94. GRB 220211B: Fermi GBM Final Real-time Localization
  95. GRB 220209A: Fermi-LAT detection
  96. GRB 220210A: Fermi-LAT detection
  97. GRB 220210A: AGILE detection
  98. GRB 220210A: BOOTES-5/JGT optical afterglow candidate discarded
  99. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  100. GRB 220210A: Swift/BAT-GUANO localization

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