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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"

11527 results found.

  1. IceCube-201120A: Upper limits from Fermi-GBM Observations
  2. Fermi trigger No 627557935: Global MASTER-Net observations report
  3. IceCube-201120A: IceCube observation of a high-energy neutrino candidate event
  4. IceCube 201114A: Swift followup of Fermi J0703.5+0505
  5. GRB 201116A: CALET Gamma-Ray Burst Monitor detection
  6. Fermi trigger No 627438255: Global MASTER-Net observations report
  7. Konus-Wind detection of GRB 201116A
  8. Fermi-LAT Gamma-ray Observations of IceCube-201114A
  9. GRB 201116A: NOT optical observations
  10. GRB 201116A: Swift-XRT afterglow detection
  11. GRB 201116A: OSN Afterglow Candidate
  12. Fermi trigger No 627198169: Global MASTER-Net observations report
  13. IceCube-201114A: No significant detection in HAWC
  14. GRB 201116A: Fermi-LAT detection
  15. GRB 201116A: Tiled Swift observations
  16. Fermi-LAT Gamma-ray Observations of IceCube-201115A
  17. GRB 201116A: BALROG localization (Fermi Trigger 627180592 / GRB 201116035)
  18. GRB 201116A: Fermi GBM Final Real-time Localization
  19. IceCube-201115A: not observable by Fermi-GBM
  20. Swift XRT observations of the Fermi-LAT source 4FGL J0658.6+0636, positionally consistent with the IceCube high-energy neutrino alert
  21. IceCube-201114A: Upper limits from Fermi GBM Observations
  22. IceCube-201115A: IceCube observation of a high-energy neutrino candidate event
  23. IceCube-201114A - IceCube observation of a high-energy neutrino candidate event
  24. Fermi-LAT Gamma-ray Observations of NuEm-201107A
  25. Fermi GRB 201111A: Global MASTER-Net observations report
  26. Konus-Wind observation of GRB 201109A
  27. GRB 201111A: Fermi GBM Final Real-time Localization
  28. IPN triangulation of GRB 201109A (short)
  29. GRB 201109A: Fermi GBM detection
  30. GRB 201104A: AstroSat CZTI detection
  31. Fermi GRB 201109A: Global MASTER-Net observations report
  32. GRB 201109A: Fermi GBM Final Real-time Localization
  33. Fermi GRB 201108A: Global MASTER-Net observations report
  34. GRB 201108A: Fermi GBM Final Real-time Localization
  35. Konus-Wind detection of GRB 201105A
  36. GRB 201104A: Swift-XRT observations
  37. Correction to GCN 28843: GBM report of GRB 201105B should have been GRB 201105A
  38. Fermi trigger No 626247072: Global MASTER-Net observations report
  39. GRB 201105B: Fermi GBM observation
  40. GRB 201105A: BALROG localization (Fermi Trigger 626247072 / GRB 201105230)
  41. GRB 201104A: BALROG localization (Fermi Trigger 626140861 / GRB 201104001)
  42. GRB 201104C: Fermi GBM Final Real-time Localization
  43. GRB 201104A: Tiled Swift observations
  44. GRB 201104A: Fermi GBM observation
  45. GRB 201104A: AGILE/MCAL detection
  46. GRB 201104A: Fermi-LAT detection
  47. Fermi GRB 201104A: Global MASTER-Net observations report
  48. GRB 201104A: Fermi GBM Final Real-time Localization
  49. Fermi GRB 201103A: Global MASTER-Net observations report
  50. GRB 201103A: Fermi GBM Final Real-time Localization
  51. Fermi GRB 201031B: Global MASTER-Net observations report
  52. GRB 201031B: BALROG localization (Fermi Trigger 625859489 / GRB 201031744)
  53. GRB 201031B: Fermi GBM Final Real-time Localization
  54. IceCube 201021A: Swift follow-up of Fermi J1725.5+1312
  55. GRB 201029A: Fermi GBM detection
  56. Fermi trigger No 625695596: Global MASTER-Net observations report
  57. GRB 201026A: Fermi GBM detection
  58. GRB 201020B: 1.3m DFOT continued optical follow-up observations
  59. GRB 201020B: HCT and GIT continued optical follow-up observations
  60. GRB 201020B: follow-up observations with Savelli Telescope
  61. GRB 201020B: 1.3m DFOT optical observations
  62. GRB 201020B: follow-up observations at Konkoly
  63. GRB 201020B: continued Mondy optical observations
  64. GRB 201020B: Redshift from GTC/OSIRIS
  65. IceCube-201021A: Optical counterpart of WISEA J172314.13+142101.5
  66. GRB 201020B: GROWTH-India Telescope optical observations
  67. Fermi-LAT Gamma-ray Observations of IceCube-201021A and detection of a new gamma-ray source, Fermi J1725.5+1312
  68. GRB 201020B: Konkoly Obs. optical detection
  69. GRB 201021C: Fermi GBM detection
  70. Konus-Wind detection of GRB 201020A
  71. GRB 201020B: Swift/UVOT Detection
  72. GRB 201020B: Swift-XRT afterglow detection
  73. IceCube-201021A: Upper limits from Fermi-GBM Observations
  74. HAWC-201019A: not observable by Fermi-GBM
  75. GRB 201020B: Mondy optical observations
  76. Konus-Wind detection of GRB 201020B
  77. GRB 201020B: Swift ToO observations
  78. GRB 201020B: Nanshan/NEXT optical afterglow confirmation
  79. GRB 201020B: MASTER bright optical afterglow detection
  80. GRB 201020B: Fermi-LAT detection
  81. IceCube-201021A: IceCube observation of a high-energy neutrino candidate event
  82. GRB 201020B: AGILE detection
  83. GRB 201021A: Fermi GBM Final Real-time Localization
  84. GRB 201020B: Fermi GBM detection
  85. GRB 201020A: Fermi GBM observation
  86. Fermi GRB 201020B: Global MASTER-Net observations report
  87. GRB 201020B: Fermi GBM Final Real-time Localization
  88. GRB 201019B: AstroSat CZTI detection
  89. GRB 201016A: Insight-HXMT/HE detection
  90. GRB 201017A: SAO RAS optical observations
  91. GRB 201017A: GROWTH-India optical upper limit
  92. GRB 201019B: Fermi GBM correction to GCN 28687
  93. GRB 201019A: Fermi GBM Final Real-time Localization
  94. GRB 201017A: MITSuME Akeno optical upper limits
  95. GRB 201019A: Fermi GBM Final Real-time Localization
  96. GRB 201017A: Assy and Mondy optical observations, possible afterglow detection
  97. GRB 201017A: Fermi GBM detection
  98. GRB 201015A: classification as long GRB
  99. GRB 201017A: Fermi GBM Final Real-time Localization
  100. Fermi GBM Sub-Threshold Detection of GRB 201015A

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