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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"

3390 results found.

  1. Swift GRB 220403B: Global MASTER-Net observations report
  2. Fermi GRB 220403A: Global MASTER-Net observations report
  3. Fermi GRB 220401B: Global MASTER-Net observations report
  4. Fermi trigger No 670501065: Global MASTER-Net observations report
  5. GRB 220330A: Fermi GBM Final Real-time Localization
  6. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  7. GRB 220324A: AstroSat CZTI detection
  8. IPN triangulation of GRB 220310A
  9. Konus-Wind detection of GRB 220310A
  10. MAXI GRB220310.02: Global MASTER-Net observations report
  11. Fermi GRB 220309A: Global MASTER-Net observations report
  12. GRB 220304A Fermi GBM detection
  13. Fermi GRB 220306A: Global MASTER-Net observations report
  14. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  15. GRB 220304A: BALROG localization (Fermi Trigger / GRB 220304228)
  16. GRB 220304A: Fermi GBM Final Real-time Localization
  17. GRB 220228A: Fermi GBM observation
  18. GRB 220228A: Fermi-LAT detection
  19. GRB 220228A: Fermi GBM Final Localization
  20. Fermi trigger No 667737010: Global MASTER-Net observations report
  21. IceCube Alert 220220.60: Global MASTER-Net observations report
  22. Fermi trigger No 666962499: Global MASTER-Net observations report
  23. GRB 220218A: Swift detection of a burst
  24. Fermi trigger No 666489765: Global MASTER-Net observations report
  25. GRB 220211B: Fermi GBM Final Real-time Localization
  26. Konus-Wind detection of GRB 220130A
  27. GRB 220128A: AstroSat CZTI detection
  28. GRB 220131A: Fermi GBM Final Real-time Localization
  29. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  30. GRB 220117B: Swift detection of a burst
  31. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  32. Fermi trigger No 663966693: Global MASTER-Net observations report
  33. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  34. Fermi GRB 220111A: Global MASTER-Net observations report
  35. Konus-Wind detection of GRB 220101A
  36. Fermi trigger No 663406755: Global MASTER-Net observations report
  37. GRB 220107A: AbAO and Terskol optical observations
  38. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  39. Fermi GRB 211229A: Global MASTER-Net observations report
  40. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  41. GRB 211227A: Liverpool Telescope upper limits
  42. GRB 211227A: LCO Optical Observations
  43. GRB 211227A: MAXI/GSC detection
  44. GRB 211225A: MITSuME Akeno optical upper limits
  45. Swift GRB 211225B: Global MASTER-Net observations report
  46. Fermi GRB 211225C: Global MASTER-Net observations report
  47. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  48. GRB 211218A: MITSuME Akeno optical upper limits
  49. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  50. MAXI GRB211218.04: Global MASTER-Net observations report
  51. GRB 211212A: Fermi GBM Final Real-time Localization
  52. Fermi GRB 211211B: Global MASTER-Net observations report
  53. Fermi trigger No 660736561: Global MASTER-Net observations report
  54. Fermi GRB 211204A: Global MASTER-Net observations report
  55. Fermi GRB 211130A: Global MASTER-Net observations report
  56. GRB 211129A: Swift/UVOT Upper Limits
  57. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  58. IPN triangulation of GRB 211120A
  59. Fermi trigger No 658971499: Global MASTER-Net observations report
  60. Fermi trigger No 658755664: Global MASTER-Net observations report
  61. GRB 211115A: MAXI/GSC detection
  62. Fermi trigger No 658214822: Global MASTER-Net observations report
  63. Fermi GRB 211109B: Global MASTER-Net observations report
  64. GRB 211023A: SAO RAS optical observations
  65. Swift Trigger 1082569 is probably not a GRB
  66. GRB 211023B: Subaru optical observation
  67. GRB 211024A: MITSuME Akeno optical observation
  68. GRB 211023B: MITSuME Akeno optical upper limits
  69. Fermi GRB 211031A: Global MASTER-Net observations report
  70. GRB 211023A: 1.3m DFOT Optical Observations
  71. GRB 211023A: Terskol optical observations
  72. Fermi GRB 211027A: Global MASTER-Net observations report
  73. GRB 210610B: Sintesz-Newton/CrAO optical observations
  74. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  75. GRB 211018A: Fermi GBM observation
  76. GRB 211018A: Fermi-LAT detection
  77. Fermi trigger No 655401471: Global MASTER-Net observations report
  78. Fermi trigger No 654854799: Global MASTER-Net observations report
  79. GRB 210928A: Fermi GBM observation
  80. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  81. Fermi GRB 210929B: Global MASTER-Net observations report
  82. GRB 210919A OSN 1.5m Source Confirmation
  83. IceCube Alert 210922.76: Global MASTER-Net observations report
  84. GRB 210919A: Swift detection of a short burst
  85. Konus-Wind observation of the recent SGR 1935+2154 activity
  86. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  87. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  88. Fermi trigger No 653084584: Global MASTER-Net observations report
  89. Fermi trigger No 653083551: Global MASTER-Net observations report
  90. Fermi trigger No 653066130: Global MASTER-Net observations report
  91. Fermi trigger No 653022153: Global MASTER-Net observations report
  92. IPN triangulation of a bright burst from SGR 1935+2154
  93. Fermi trigger No 652944960: Global MASTER-Net observations report
  94. Fermi trigger No 652906639: Global MASTER-Net observations report
  95. Fermi trigger No 652585475: Global MASTER-Net observations report
  96. Fermi GRB 210903A: Global MASTER-Net observations report
  97. GRB 210827A: BOOTES-5/JGT optical upper limit
  98. Integral GRB210829.14: Global MASTER-Net observations report
  99. Fermi GRB 210827A: Global MASTER-Net observations report
  100. GRB 210824A: Fermi GBM Observation

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