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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"

913 results found.

  1. Fermi GBM Sub-Threshold Detection of GRB 200517A
  2. GRB 200517A: Swift-XRT afterglow detection
  3. GRB 200514A: AstroSat CZTI detection
  4. GRB 200517A: Tiled Swift observations
  5. GRB 200517A: MAXI/GSC detection
  6. GRB 200514A: MITSuME Akeno optical upper limits
  7. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  8. GRB 200514A: MAXI/GSC detection
  9. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  10. SGR 1935+2154: MAXI/GSC detection
  11. GRB 200320B: MAXI/GSC detection
  12. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  13. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  14. GRB 200310A: MAXI/GSC detection
  15. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  16. LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
  19. LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
  20. LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
  21. GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
  22. GRB 200205A / Swift trigger 954304: VLT optical observations
  23. GRB 200205A: MAXI/GSC detection
  24. MAXI GRB200205.29: Global MASTER-Net observations report
  25. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  27. LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
  28. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  29. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  30. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  31. GRB 200105A: MAXI/GSC detection
  32. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  33. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  34. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  35. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  36. LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
  37. LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
  39. LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
  40. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  41. GRB 191106A: Swift/UVOT Upper Limits
  42. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  43. Fermi trigger No 594557071: Global MASTER-Net observations report
  44. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  45. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  46. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  47. LIGO/Virgo S190924h: Identification of a GW compact binary merger candidate
  48. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  49. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  50. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  51. Swift Trigger 924641 is an outburst from MAXI J1807+132
  52. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  53. GRB 190823A: Swift-XRT afterglow detection
  54. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  55. GRB 190828A: Swift-XRT observations
  56. GRB 190828A: Tiled Swift observations
  57. LIGO/Virgo S190828l: Coverage and upper limits from MAXI/GSC observations
  58. LIGO/Virgo S190828j: Coverage and upper limits from MAXI/GSC observations
  59. GRB 190828A: MAXI/GSC detection
  60. GRB 190823A: Swift-XRT observations
  61. GRB 190823A: Tiled Swift observations
  62. GRB 190823A: MAXI/GSC detection
  63. Fermi GBM-190816: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo S190814bv: Coverage and upper limits from MAXI/GSC observations
  65. IPN triangulation of GRB 190805B
  66. LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations
  67. GRB 190805B: AstroSat CZTI detection
  68. GRB 190804B: Swift-XRT afterglow detection
  69. Konus-Wind observation of GRB 190805B
  70. GRB 190805B: Swift-XRT observations
  71. GRB 190805B: Fermi GBM detection
  72. GRB 190805B: Tiled Swift observations
  73. GRB 190804B: Swift-XRT observations
  74. GRB 190805B: MAXI/GSC detection
  75. MAXI GRB190804.33 Global MASTER-Net observations report
  76. GRB 190804B: Tiled Swift observations
  77. GRB 190804B: MAXI/GSC detection
  78. LIGO/Virgo S190728q: Coverage and upper limits from MAXI/GSC observations
  79. LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo S190720a: Coverage and upper limits from MAXI/GSC observations
  81. LIGO/Virgo S190718y: Coverage and upper limits from MAXI/GSC observations
  82. GRB 190714A: an X-ray flare from 2E 1624.6+1504/UCAC4 525-061488
  83. GRB 190708B: confirmation of the X-ray afterglow
  84. GRB 190714A: Tiled Swift observations
  85. GRB 190714A: MAXI/GSC detection
  86. GRB 190708B: Swift-XRT observations
  87. Konus-Wind observation of GRB 190708B
  88. GRB 190708B: Tiled Swift observations
  89. MAXI GRB190708.83 Global MASTER-Net observations report
  90. GRB 190708B: MAXI/GSC detection
  91. LIGO/Virgo S190707q: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo S190706ai: Coverage and upper limits from MAXI/GSC observations
  93. GRB 190706A: MAXI/GSC detection
  94. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  95. GRB 190701A: MAXI/GSC detection
  96. LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations
  97. IceCube Alert 190629.81 Global MASTER-Net observations report
  98. LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
  100. IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations

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