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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"

5157 results found.

  1. GRB 211207A: Swift-XRT refined Analysis
  2. Swift GRB 211207A: Global MASTER-Net observations report
  3. GRB 211207A: Swift detection of a burst with an optical counterpart
  4. IPN triangulation of GRB 211204C
  5. Fermi GRB 211204B: Global MASTER-Net observations report
  6. GRB 211124A: Fermi GBM Observation
  7. IPN triangulation of GRB 211130A
  8. GRB 211129A: Swift-XRT refined Analysis
  9. IceCube-211125A: Upper limits from a search for additional neutrino events in IceCube
  10. IPN triangulation of GRB 211118A
  11. GRB 211129A: MITSuME Akeno optical upper limits
  12. Konus-Wind detection of GRB 211120A
  13. Chandra observations of GRB 210905A
  14. IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube
  15. IceCube Alert 211123.60: Global MASTER-Net observations report
  16. Fermi trigger No 659413798: Global MASTER-Net observations report
  17. Fermi trigger No 659183098: Global MASTER-Net observations report
  18. Fermi trigger No 658971499: Global MASTER-Net observations report
  19. IceCube-211116A: Upper limits from a search for additional neutrino events in IceCube
  20. Fermi trigger No 658755664: Global MASTER-Net observations report
  21. Konus-Wind detection of GRB 211107B
  22. Fermi trigger No 658686687: Global MASTER-Net observations report
  23. GRB 211115A: MAXI/GSC detection
  24. Fermi GRB 211112A: Global MASTER-Net observations report
  25. Fermi trigger No 658214822: Global MASTER-Net observations report
  26. Fermi GRB 211109B: Global MASTER-Net observations report
  27. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  28. GRB 211024A: MITSuME Akeno optical observation
  29. GRB 211023B: MITSuME Akeno optical upper limits
  30. GRB 211024A: 1.3m DFOT observations
  31. GRB 211024A: Fermi GBM detection
  32. IceCube-211023A: Upper limits from a search for additional neutrino events in IceCube
  33. GRB 211025A: Swift-XRT refined Analysis
  34. GRB 211024B: Swift-XRT refined Analysis
  35. GRB 211023A: 1.5m OSN optical observation
  36. GRB 211024B: Nanshan/NEXT optical afterglow detection
  37. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  38. Fermi GRB 211023A: Global MASTER-Net observations report
  39. GRB 211023B: Swift-XRT refined Analysis
  40. Fermi GRB 211024A: Global MASTER-Net observations report
  41. GRB 211024A: Fermi GBM Final Real-time Localization
  42. IceCube Alert 211023.36: Global MASTER-Net observations report
  43. Fermi trigger No 656506979: Global MASTER-Net observations report
  44. Swift trigger 1078701: MITSuME Akeno optical upper limits
  45. Fermi trigger No 655673024: Global MASTER-Net observations report
  46. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  47. Fermi trigger No 655401471: Global MASTER-Net observations report
  48. GRB 210928A: Fermi GBM observation
  49. Fermi trigger No 654739449: Global MASTER-Net observations report
  50. Swift Trigger 1076121 is not a GRB
  51. GRB 210930A: Swift-XRT refined Analysis
  52. Fermi GRB 210929B: Global MASTER-Net observations report
  53. IceCube-210922A: JCMT/SCUBA2 observations
  54. GRB 210924A: Fermi GBM Final Real-time Localization
  55. GRB 210919A: MITSuME Akeno optical upper limits
  56. GRB 210912A: Swift-XRT refined Analysis
  57. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  58. Fermi trigger No 653066776: Global MASTER-Net observations report
  59. Fermi trigger No 653084584: Global MASTER-Net observations report
  60. Fermi trigger No 653083551: Global MASTER-Net observations report
  61. Fermi trigger No 653066130: Global MASTER-Net observations report
  62. Fermi trigger No 653071808: Global MASTER-Net observations report
  63. Fermi trigger No 653049776: Global MASTER-Net observations report
  64. Fermi trigger No 653022153: Global MASTER-Net observations report
  65. Fermi trigger No 652981861: Global MASTER-Net observations report
  66. GECAM observations of a series of bursts from SGR J1935+2154
  67. Fermi trigger No 652911693: Global MASTER-Net observations report
  68. Fermi trigger No 652906639: Global MASTER-Net observations report
  69. GRB 210905A: AstroSat CZTI detection
  70. Fermi trigger No 652585475: Global MASTER-Net observations report
  71. GRB 210610A: Maidanak and AbAO optical observations
  72. Fermi GRB 210903B: Global MASTER-Net observations report
  73. GRB 210827A: Fermi GBM Observation
  74. GRB 210826A: AstroSat CZTI detection
  75. Fermi GRB 210827A: Global MASTER-Net observations report
  76. GRB 210827A: Fermi GBM Final Real-time Localization
  77. Fermi GRB 210826A: Global MASTER-Net observations report
  78. GRB 210824A: MITSuME Akeno optical upper limits
  79. GRB 210822A: TSHAO continued optical observation
  80. GRB 210822A: VLA detection
  81. Swift GRB 210824A: Global MASTER-Net observations report
  82. GRB 210824A: Fermi GBM Observation
  83. Fermi GRB 210824A: Global MASTER-Net observations report
  84. GRB 210824A: Nanshan/NEXT optical upper limit
  85. GRB 210824A: Swift-XRT refined Analysis
  86. GRB 210824A: Fermi GBM Final Real-time Localization
  87. GRB 210822A: Swift-XRT refined Analysis
  88. Fermi GRB 210822B: Global MASTER-Net observations report
  89. GRB 210822B: Fermi GBM Final Real-time Localization
  90. Swift GRB 210822A: Global MASTER-Net observations report
  91. Fermi GRB 210821A: Global MASTER-Net observations report
  92. GRB 210820A: Swift-XRT refined Analysis
  93. GRB 210818A: Swift-XRT refined Analysis
  94. Fermi GRB 210813A: Global MASTER-Net observations report
  95. GRB 210807C: Swift-BAT refined analysis
  96. GRB 210807C: Enhanced Swift-XRT position
  97. Fermi GRB 210807C: Global MASTER-Net observations report
  98. GRB 210807C: Swift detection of a burst
  99. GRB 210807C: Fermi GBM Final Real-time Localization
  100. IPN Triangulation of a bright burst from SGR 1935+2154

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