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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"

860 results found.

  1. GRB 210602A: CALET Gamma-Ray Burst Monitor detection
  2. GRB 210602A: MAXI/GSC detection
  3. GRB 210528B: DDOTI Upper Limits on the Afterglow
  4. MAXI GRB210528.95: Global MASTER-Net observations report
  5. GRB 210528B: MAXI/GSC detection
  6. MAXI GRB210521.54: Global MASTER-Net observations report
  7. GRB 210521A: MAXI/GSC detection
  8. Swift Detection of MAXI J1803-298 including an optical counterpart
  9. MAXI GRB210501.83: Global MASTER-Net observations report
  10. MAXI GRB210320.89: Global MASTER-Net observations report
  11. GRB 210320A: MAXI/GSC detection
  12. Konus-Wind detection of GRB 210222A
  13. GRB 210222A: CALET Gamma-Ray Burst Monitor detection
  14. GRB 210222A: MAXI/GSC detection
  15. SGR 1935+2154: MAXI/GSC detection
  16. NuEm-210111A: MAXI/GSC upper limit
  17. MAXI GRB210110.64: Global MASTER-Net observations report
  18. GRB 210110A: MAXI/GSC detection
  19. GRB 210109A: MAXI/GSC detection
  20. GRB 210102B: further Swift-XRT observations
  21. GRB 210102B: Assy optical afterglow identification
  22. GRB 210102B: Tiled Swift observations
  23. GRB 210102B: Assy optical observations
  24. GRB 210102B: Swift-XRT observations
  25. MAXI GRB210102.38: Global MASTER-Net observations report
  26. GRB 210102B: Tiled Swift observations
  27. GRB 210102B: MAXI/GSC detection
  28. IceCube-201209A : MAXI/GSC upper limit
  29. MAXI GRB201021.68: Global MASTER-Net observations report
  30. GRB 201021B MAXI/GSC detection
  31. GRB 200903D: MAXI/GSC detection
  32. GRB 200809B: Fermi GBM detection
  33. GRB 200809B: Swift-XRT afterglow detection
  34. GRB 200809B: MAXI/GSC detection
  35. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  36. GRB 200615B: MAXI/GSC detection
  37. GRB 200517A: Swift-XRT Confirmation of afterglow
  38. Fermi GBM Sub-Threshold Detection of GRB 200517A
  39. GRB 200517A: Swift-XRT afterglow detection
  40. GRB 200514A: AstroSat CZTI detection
  41. GRB 200517A: Tiled Swift observations
  42. GRB 200517A: MAXI/GSC detection
  43. GRB 200514A: MITSuME Akeno optical upper limits
  44. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  45. GRB 200514A: MAXI/GSC detection
  46. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  47. SGR 1935+2154: MAXI/GSC detection
  48. GRB 200320B: MAXI/GSC detection
  49. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  50. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  51. GRB 200310A: MAXI/GSC detection
  52. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  53. LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
  54. LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
  55. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
  56. LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
  57. LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
  58. GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
  59. GRB 200205A / Swift trigger 954304: VLT optical observations
  60. GRB 200205A: MAXI/GSC detection
  61. MAXI GRB200205.29: Global MASTER-Net observations report
  62. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  63. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
  65. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  66. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  67. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  68. GRB 200105A: MAXI/GSC detection
  69. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  70. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  71. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  72. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  73. LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
  74. LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
  75. LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
  76. LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
  77. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  78. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  79. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  81. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  82. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  83. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  84. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  85. Swift Trigger 924641 is an outburst from MAXI J1807+132
  86. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  87. GRB 190823A: Swift-XRT afterglow detection
  88. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  89. GRB 190828A: Swift-XRT observations
  90. GRB 190828A: Tiled Swift observations
  91. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
  93. GRB 190828A: MAXI/GSC detection
  94. GRB 190823A: Swift-XRT observations
  95. GRB 190823A: Tiled Swift observations
  96. GRB 190823A: MAXI/GSC detection
  97. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  98. LIGO/Virgo S190814bv: Coverage and upper limits from MAXI/GSC observations
  99. IPN triangulation of GRB 190805B
  100. LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations

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