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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"

911 results found.

  1. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  2. GRB 211115A: MAXI/GSC detection
  3. MAXI GRB210709.93: Global MASTER-Net observations report
  4. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  5. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  6. MAXI GRB210607.82: Global MASTER-Net observations report
  7. Konus-Wind detection of GRB 210602A
  8. MAXI GRB210602.50: Global MASTER-Net observations report
  9. GRB 210602A: CALET Gamma-Ray Burst Monitor detection
  10. GRB 210602A: MAXI/GSC detection
  11. GRB 210528B: DDOTI Upper Limits on the Afterglow
  12. MAXI GRB210528.95: Global MASTER-Net observations report
  13. GRB 210528B: MAXI/GSC detection
  14. MAXI GRB210521.54: Global MASTER-Net observations report
  15. GRB 210521A: MAXI/GSC detection
  16. Swift Detection of MAXI J1803-298 including an optical counterpart
  17. MAXI GRB210501.83: Global MASTER-Net observations report
  18. MAXI GRB210320.89: Global MASTER-Net observations report
  19. GRB 210320A: MAXI/GSC detection
  20. Konus-Wind detection of GRB 210222A
  21. GRB 210222A: CALET Gamma-Ray Burst Monitor detection
  22. GRB 210222A: MAXI/GSC detection
  23. SGR 1935+2154: MAXI/GSC detection
  24. NuEm-210111A: MAXI/GSC upper limit
  25. MAXI GRB210110.64: Global MASTER-Net observations report
  26. GRB 210110A: MAXI/GSC detection
  27. GRB 210109A: MAXI/GSC detection
  28. GRB 210102B: further Swift-XRT observations
  29. GRB 210102B: Assy optical afterglow identification
  30. GRB 210102B: Tiled Swift observations
  31. GRB 210102B: Assy optical observations
  32. GRB 210102B: Swift-XRT observations
  33. MAXI GRB210102.38: Global MASTER-Net observations report
  34. GRB 210102B: Tiled Swift observations
  35. GRB 210102B: MAXI/GSC detection
  36. IceCube-201209A : MAXI/GSC upper limit
  37. GRB 201128A: Swift/UVOT Upper Limits
  38. GRB 201029A: Swift/UVOT Upper Limits
  39. MAXI GRB201021.68: Global MASTER-Net observations report
  40. GRB 201021B MAXI/GSC detection
  41. GRB 200903D: MAXI/GSC detection
  42. GRB 200809B: Fermi GBM detection
  43. GRB 200809B: Swift-XRT afterglow detection
  44. GRB 200809B: MAXI/GSC detection
  45. GRB 200806A: Enhanced Swift-XRT position
  46. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  47. GRB 200615B: MAXI/GSC detection
  48. Fermi GRB 200530A: Global MASTER-Net observations report
  49. GRB 200517A: Swift-XRT Confirmation of afterglow
  50. GRB 200519A: Swift/UVOT Detection
  51. Fermi GBM Sub-Threshold Detection of GRB 200517A
  52. GRB 200517A: Swift-XRT afterglow detection
  53. GRB 200514A: AstroSat CZTI detection
  54. GRB 200517A: Tiled Swift observations
  55. GRB 200517A: MAXI/GSC detection
  56. GRB 200514A: MITSuME Akeno optical upper limits
  57. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  58. GRB 200514A: MAXI/GSC detection
  59. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  60. SGR 1935+2154: MAXI/GSC detection
  61. IceCube Alert 200410.97: Global MASTER-Net observations report
  62. GRB 200320B: MAXI/GSC detection
  63. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  65. GRB 200310A: MAXI/GSC detection
  66. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  67. LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
  68. LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
  70. LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
  71. LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
  72. GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
  73. GRB 200205A / Swift trigger 954304: VLT optical observations
  74. GRB 200205A: MAXI/GSC detection
  75. MAXI GRB200205.29: Global MASTER-Net observations report
  76. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  77. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  78. LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
  79. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  81. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  82. GRB 200105A: MAXI/GSC detection
  83. GRB 191228A: Swift/UVOT Upper Limits
  84. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  85. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  86. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  87. LIGO/Virgo S191215w: Global MASTER-Net observations report
  88. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  89. LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
  90. LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
  91. LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
  93. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  94. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  95. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  96. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  97. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  98. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  100. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations

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