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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"

11546 results found.

  1. GRB 201130A: DDOTI Observations
  2. Fermi GRB 201130A: Global MASTER-Net observations report
  3. GRB 201130A: Fermi GBM Final Real-time Localization
  4. Fermi trigger No 628278856: Global MASTER-Net observations report
  5. Fermi trigger No 628140709: DDOTI/OAN optical observations report
  6. Fermi trigger No 628140709: Global MASTER-Net observations report
  7. GRB 201121A: Insight-HXMT/HE detection
  8. GRB 200826A: TNG and LBT constraints on a supernova bump
  9. IceCube-201114A: DECam observations and candidate optical counterpart
  10. Fermi-LAT Gamma-ray Observations of IceCube-201120A
  11. Fermi trigger No 627645769: Global MASTER-Net observations report
  12. IceCube-201120A: Swift-XRT non-detection of 4FGL J2028.6+4110e
  13. Fermi GRB 201121A: Global MASTER-Net observations report
  14. GRB 201121B: Fermi GBM Final Real-time Localization
  15. GRB 201121A: BALROG localization (Fermi Trigger 627614994 / GRB 201121062)
  16. GRB 201121A: Fermi GBM Final Real-time Localization
  17. Fermi GRB 201120B: Global MASTER-Net observations report
  18. GRB 201120B: Fermi GBM Final Localization
  19. GRB 201120A: Fermi GBM Final Localization
  20. IceCube-201120A: Upper limits from Fermi-GBM Observations
  21. Fermi trigger No 627557935: Global MASTER-Net observations report
  22. IceCube-201120A: IceCube observation of a high-energy neutrino candidate event
  23. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  24. GRB 201116A: CALET Gamma-Ray Burst Monitor detection
  25. Fermi trigger No 627438255: Global MASTER-Net observations report
  26. Konus-Wind detection of GRB 201116A
  27. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  28. GRB 201116A: NOT optical observations
  29. GRB 201116A: Swift-XRT afterglow detection
  30. GRB 201116A: OSN Afterglow Candidate
  31. Fermi trigger No 627198169: Global MASTER-Net observations report
  32. IceCube-201114A: No significant detection in HAWC
  33. GRB 201116A: Fermi-LAT detection
  34. GRB 201116A: Tiled Swift observations
  35. Fermi-LAT Gamma-ray Observations of IceCube-201115A
  36. GRB 201116A: BALROG localization (Fermi Trigger 627180592 / GRB 201116035)
  37. GRB 201116A: Fermi GBM Final Real-time Localization
  38. IceCube-201115A: not observable by Fermi-GBM
  39. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  40. IceCube-201114A: Upper limits from Fermi GBM Observations
  41. IceCube-201115A: IceCube observation of a high-energy neutrino candidate event
  42. IceCube-201114A - IceCube observation of a high-energy neutrino candidate event
  43. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  44. Fermi GRB 201111A: Global MASTER-Net observations report
  45. Konus-Wind observation of GRB 201109A
  46. GRB 201111A: Fermi GBM Final Real-time Localization
  47. IPN triangulation of GRB 201109A (short)
  48. GRB 201109A: Fermi GBM detection
  49. GRB 201104A: AstroSat CZTI detection
  50. Fermi GRB 201109A: Global MASTER-Net observations report
  51. GRB 201109A: Fermi GBM Final Real-time Localization
  52. Fermi GRB 201108A: Global MASTER-Net observations report
  53. GRB 201108A: Fermi GBM Final Real-time Localization
  54. Konus-Wind detection of GRB 201105A
  55. GRB 201104A: Swift-XRT observations
  56. Correction to GCN 28843: GBM report of GRB 201105B should have been GRB 201105A
  57. Fermi trigger No 626247072: Global MASTER-Net observations report
  58. GRB 201105B: Fermi GBM observation
  59. GRB 201105A: BALROG localization (Fermi Trigger 626247072 / GRB 201105230)
  60. GRB 201104A: BALROG localization (Fermi Trigger 626140861 / GRB 201104001)
  61. GRB 201104C: Fermi GBM Final Real-time Localization
  62. GRB 201104A: Tiled Swift observations
  63. GRB 201104A: Fermi GBM observation
  64. GRB 201104A: AGILE/MCAL detection
  65. GRB 201104A: Fermi-LAT detection
  66. Fermi GRB 201104A: Global MASTER-Net observations report
  67. GRB 201104A: Fermi GBM Final Real-time Localization
  68. Fermi GRB 201103A: Global MASTER-Net observations report
  69. GRB 201103A: Fermi GBM Final Real-time Localization
  70. Fermi GRB 201031B: Global MASTER-Net observations report
  71. GRB 201031B: BALROG localization (Fermi Trigger 625859489 / GRB 201031744)
  72. GRB 201031B: Fermi GBM Final Real-time Localization
  73. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  74. GRB 201029A: Fermi GBM detection
  75. Fermi trigger No 625695596: Global MASTER-Net observations report
  76. GRB 201026A: Fermi GBM detection
  77. GRB 201020B: 1.3m DFOT continued optical follow-up observations
  78. GRB 201020B: HCT and GIT continued optical follow-up observations
  79. GRB 201020B: follow-up observations with Savelli Telescope
  80. GRB 201020B: 1.3m DFOT optical observations
  81. GRB 201020B: follow-up observations at Konkoly
  82. GRB 201020B: continued Mondy optical observations
  83. GRB 201020B: Redshift from GTC/OSIRIS
  84. IceCube-201021A: Optical counterpart of WISEA J172314.13+142101.5
  85. GRB 201020B: GROWTH-India Telescope optical observations
  86. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  87. GRB 201020B: Konkoly Obs. optical detection
  88. GRB 201021C: Fermi GBM detection
  89. Konus-Wind detection of GRB 201020A
  90. GRB 201020B: Swift/UVOT Detection
  91. GRB 201020B: Swift-XRT afterglow detection
  92. IceCube-201021A: Upper limits from Fermi-GBM Observations
  93. HAWC-201019A: not observable by Fermi-GBM
  94. GRB 201020B: Mondy optical observations
  95. Konus-Wind detection of GRB 201020B
  96. GRB 201020B: Swift ToO observations
  97. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  98. GRB 201020B: MASTER bright optical afterglow detection
  99. GRB 201020B: Fermi-LAT detection
  100. IceCube-201021A: IceCube observation of a high-energy neutrino candidate event

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