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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"

11528 results found.

  1. GRB 201227A: AGILE detection of a burst
  2. Fermi trigger No 630681391: Global MASTER-Net observations report
  3. GRB 201223A: 1.3m DFOT and 1.04m ST optical observations
  4. GRB 201223A: Fermi GBM Detection
  5. GRB 201221A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  6. GRB 201221B: Insight-HXMT/HE detection
  7. Fermi trigger No 630389391: Global MASTER-Net observations report
  8. Fermi GRB 201222B: Global MASTER-Net observations report
  9. GRB 201221D: Fermi GBM detection
  10. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  11. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  12. IceCube-201222A: not observable by Fermi-GBM
  13. GRB 201222B: BALROG localization (Fermi Trigger / GRB 201222461)
  14. GRB 201222B: Fermi GBM Final Real-time Localization
  15. Fermi GRB 201221E: Global MASTER-Net observations report
  16. IceCube-201222A: IceCube observation of a high-energy neutrino candidate event
  17. GRB 201222A: Fermi GBM Final Real-time Localization
  18. GRB 201221E: Fermi GBM Final Real-time Localization
  19. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  20. Fermi GBM Sub-Threshold Detection of GRB 201221A
  21. IceCube-201221A: not observable by Fermi-GBM
  22. IceCube-201221A: IceCube observation of a high-energy neutrino candidate event
  23. GRB 201221B: Fermi GBM Final Real-time Localization
  24. Konus-Wind observation of GRB 201218A
  25. IPN triangulation of GRB 201218A
  26. Fermi GRB 201218B: Global MASTER-Net observations report
  27. GRB 201218B: Fermi GBM Final Real-time Localization
  28. Fermi GRB 201218A: Global MASTER-Net observations report
  29. GRB201216C: No significant detection in HAWC
  30. Konus-Wind detection of GRB 201216C
  31. GRB 201218A: BALROG localization (Fermi Trigger 629957660 / GRB 201218177)
  32. GRB 201218A: Fermi GBM Final Real-time Localization
  33. Fermi GRB 201217A: Global MASTER-Net observations report
  34. GRB 201217A: Fermi GBM Final Localization
  35. GRB 201216C: VLT X-shooter spectroscopy and potential high redshift of a VHE-emitting GRB
  36. GRB 201216C: Fermi-LAT upper limit
  37. GRB 201216C: MAGIC detection in very high energy gamma rays
  38. GRB 201216C: AstroSat CZTI detection
  39. GRB 201216C: Fermi GBM detection
  40. GRB 201216A: Fermi GBM detection
  41. GRB 201216C: FRAM-ORM afterglow confirmation
  42. GRB 201216A: Swift-XRT observations
  43. GRB 201216C: VLT afterglow candidate discovery
  44. GRB 201216C: Fermi GBM Final Real-time Localization
  45. Fermi GRB 201216A: Global MASTER-Net observations report
  46. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  47. GRB 201216A: Fermi GBM Final Real-time Localization
  48. GRB 201214B: MITSuME Akeno optical upper limits
  49. GRB 201214B: Lowell Discovery Telescope optical observations
  50. Fermi GRB 201215A: Global MASTER-Net observations report
  51. GRB 201215A: BALROG localization (Fermi Trigger 629706213 / GRB 201215266)
  52. GRB 201215A: Fermi GBM Final Real-time Localization
  53. GRB 201214B: Swift BAT location of short burst
  54. Fermi GRB 201214B: Global MASTER-Net observations report
  55. GRB 201214B: Fermi GBM Final Real-time Localization
  56. GRB 201213A: Fermi GBM Final Real-time Localization
  57. IceCube-201209A: Upper limits from Fermi-GBM Observations
  58. Fermi-LAT Gamma-ray Observations of IceCube-201209A
  59. IPN triangulation of GRB 201207A
  60. GRB 201208A: Swift-XRT afterglow detection
  61. GRB 201208A: Fermi GBM observation
  62. GRB 201208A: LCO observations
  63. IceCube-201209A: IceCube observation of a high-energy neutrino candidate event
  64. GRB 201207A: AGILE detection
  65. GRB 201208A: Fermi-LAT detection
  66. GRB 201208A: Swift ToO observations
  67. GRB 201208A: AstroSat CZTI detection
  68. GRB 201207A: AstroSat CZTI detection
  69. Fermi GRB 201208A: Global MASTER-Net observations report
  70. GRB 201208A: Fermi GBM Final Real-time Localization
  71. Fermi GRB 201207A: Global MASTER-Net observations report
  72. GRB 201207A: Fermi GBM Final Real-time Localization
  73. Swift follow-up observations of the flat spectrum radio quasar PMN J0206-1150 in the error region of IceCube-201130A
  74. GRB201130A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 628407054)
  75. Swift observations of the Fermi-LAT source 4FGL J0206.4-1151 in the error region of IceCube-201130A
  76. Fermi-LAT Gamma-ray Observations of IceCube-201130A
  77. IceCube-201130A: Not observable by Fermi-GBM
  78. GRB 201201A: DDOTI Observations
  79. Fermi GRB 201201A: Global MASTER-Net observations report
  80. GRB 201201A: Fermi GBM Final Real-time Localization
  81. GRB 201128B: Swift/BAT-GUANO detection and arcminute localization
  82. IceCube-201130A: IceCube observation of a high-energy neutrino candidate event
  83. GRB 201130A: DDOTI Observations
  84. Fermi GRB 201130A: Global MASTER-Net observations report
  85. GRB 201130A: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 628278856: Global MASTER-Net observations report
  87. Fermi trigger No 628140709: DDOTI/OAN optical observations report
  88. Fermi trigger No 628140709: Global MASTER-Net observations report
  89. GRB 201121A: Insight-HXMT/HE detection
  90. GRB 200826A: TNG and LBT constraints on a supernova bump
  91. IceCube-201114A: DECam observations and candidate optical counterpart
  92. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  93. Fermi trigger No 627645769: Global MASTER-Net observations report
  94. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  95. Fermi GRB 201121A: Global MASTER-Net observations report
  96. GRB 201121B: Fermi GBM Final Real-time Localization
  97. GRB 201121A: BALROG localization (Fermi Trigger 627614994 / GRB 201121062)
  98. GRB 201121A: Fermi GBM Final Real-time Localization
  99. Fermi GRB 201120B: Global MASTER-Net observations report
  100. GRB 201120B: Fermi GBM Final Localization

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