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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').
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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"

4256 results found.

  1. IPN triangulation of a bright burst from SGR 1935+2154
  2. Konus-Wind observation of the recent SGR 1935+2154 activity
  3. GRB 220118A: MITSuME Akeno optical observation
  4. Swift GRB 220118A: Global MASTER-Net observations report
  5. GRB 220118A: Swift detection of a burst with an optical counterpart
  6. GECAM observations of a series of bursts from SGR J1935+2154
  7. Fermi trigger No 663966693: Global MASTER-Net observations report
  8. GECAM observations of a series of bursts from SGR J1935+2154
  9. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  10. AGILE observations of a burst from SGR 1935+2154
  11. GECAM observations of a series of bursts from SGR J1935+2154
  12. Fermi Gamma-ray Burst Monitor trigger 220111325/663580106 is not a GRB
  13. GECAM observations of a series of bursts from SGR J1935+2154
  14. GECAM observation of a burst from SGR J1555.2-5402
  15. GECAM detection of a short burst from SGR 1935+2154
  16. Fermi trigger No 663129379: Global MASTER-Net observations report
  17. GECAM observations of a series of bursts from SGR J1935+2154
  18. GRB 220101A: iTelescope optical observations
  19. GRB 220104A：GECAM detection
  20. GRB 211229B: Fermi GBM observation
  21. IPN triangulation of GRB 211219A
  22. GRB 211231A: GECAM detection
  23. GRB 211229B: AGILE detection
  24. GRB 211229A: Fermi GBM observation
  25. GRB 211229B: GECAM detection
  26. Fermi GRB 211229B: Global MASTER-Net observations report
  27. GRB 211229B: Fermi GBM Final Real-time Localization
  28. GRB 211229A: Swift/BAT-GUANO arcminute localization
  29. GRB 211229A: GECAM detection
  30. Fermi GRB 211229A: Global MASTER-Net observations report
  31. GRB 211229A: Fermi GBM Final Real-time Localization
  32. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  33. Fermi GRB 211225C: Global MASTER-Net observations report
  34. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  35. Fermi trigger No 662084433: Global MASTER-Net observations report
  36. GRB 211106A: Third HST Observation
  37. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  38. AGILE observations of a bright burst from SGR 1935+2154
  39. GRB 211223C: Swift detection of a burst
  40. GRB 211223A: GECAM detection
  41. GRB 211218A: MITSuME Akeno optical upper limits
  42. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  43. MAXI GRB211218.04: Global MASTER-Net observations report
  44. GRB 211217A: GECAM detection
  45. GRB 211216B: GECAM detection
  46. GRB 211216A: GECAM detection
  47. Fermi GRB 211216A: Global MASTER-Net observations report
  48. GRB 211211B: GECAM detection
  49. Fermi GRB 211211B: Global MASTER-Net observations report
  50. Fermi trigger No 660736561: Global MASTER-Net observations report
  51. IPN triangulation of GRB 211204C
  52. GRB 211204C: GECAM detection
  53. Fermi GRB 211204B: Global MASTER-Net observations report
  54. GRB 211124A: Fermi GBM Observation
  55. GRB 211201A: GECAM detection
  56. GRB 211106A: GECAM detection
  57. GRB 211129A: Swift-BAT refined analysis
  58. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  59. GRB 211129A: Fermi GBM observation
  60. Swift GRB 211129A: Global MASTER-Net observations report
  61. GRB 211129A: Nanshan/NEXT optical upper limit
  62. GRB 211129A: MITSuME Akeno optical upper limits
  63. IceCube Alert 211125.27: Global MASTER-Net observations report
  64. IPN triangulation of GRB 211124A (short)
  65. GRB 211124A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  66. Fermi trigger No 659106591: Global MASTER-Net observations report
  67. GRB 211120A: GECAM detection
  68. Fermi trigger No 658971499: Global MASTER-Net observations report
  69. Fermi trigger No 658755664: Global MASTER-Net observations report
  70. GRB 211115A: MAXI/GSC detection
  71. Fermi GRB 211112A: Global MASTER-Net observations report
  72. GRB 211110A: GECAM detection
  73. Fermi trigger No 658214822: Global MASTER-Net observations report
  74. GRB 211107A: GECAM detection
  75. Fermi GRB 211109B: Global MASTER-Net observations report
  76. GRB 211109C: GECAM detection
  77. GRB 211105A: GECAM detection
  78. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  79. GRB 211024A: MITSuME Akeno optical observation
  80. GRB 211102B: GECAM detection
  81. Fermi GRB 211102A: Global MASTER-Net observations report
  82. GRB 211023B: MITSuME Akeno optical upper limits
  83. Fermi GRB 211031A: Global MASTER-Net observations report
  84. IPN triangulation of GRB 211022A
  85. GRB 211023A: Terskol optical observations
  86. GECAM detection of a short burst probably from SGR J1555.2-5402
  87. GRB 211024A: GECAM detection
  88. GRB 211022A: GECAM detection
  89. Fermi trigger No 656506979: Global MASTER-Net observations report
  90. GRB 211018A: Detection by GRBAlpha
  91. Fermi trigger No 656288898: Global MASTER-Net observations report
  92. Fermi trigger No 655673024: Global MASTER-Net observations report
  93. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  94. Fermi trigger No 655646385: Global MASTER-Net observations report
  95. Fermi Gamma-ray Burst Monitor trigger 211008665/655401471 is not a GRB
  96. Fermi trigger No 655401471: Global MASTER-Net observations report
  97. GECAM observation of a burst from SGR J1555.2-5402
  98. SGR 1935+2154: Swift/BAT-GUANO detection and arcminute localization
  99. GRB 210928A: Swift-XRT analysis (replaces GCN 30914)
  100. GRB 210927B: GECAM detection

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