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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"

897 results found.

  1. GRB 211225A: MITSuME Akeno optical upper limits
  2. GRB 211226A: AGILE/MCAL detection of a burst
  3. MAXI GRB211225.14: Global MASTER-Net observations report
  4. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  5. GRB 211218A: MITSuME Akeno optical upper limits
  6. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  7. MAXI GRB211218.04: Global MASTER-Net observations report
  8. GRB 211115A: CALET Gamma-Ray Burst Monitor detection
  9. GRB 211115A: MAXI/GSC detection
  10. MAXI GRB210709.93: Global MASTER-Net observations report
  11. Fermi trigger No 645857659: Global MASTER-Net observations report
  12. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  13. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  14. MAXI GRB210607.82: Global MASTER-Net observations report
  15. Konus-Wind detection of GRB 210602A
  16. MAXI GRB210602.50: Global MASTER-Net observations report
  17. GRB 210602A: CALET Gamma-Ray Burst Monitor detection
  18. GRB 210602A: MAXI/GSC detection
  19. GRB 210528B: DDOTI Upper Limits on the Afterglow
  20. MAXI GRB210528.95: Global MASTER-Net observations report
  21. GRB 210528B: MAXI/GSC detection
  22. MAXI GRB210521.54: Global MASTER-Net observations report
  23. GRB 210521A: MAXI/GSC detection
  24. Swift Detection of MAXI J1803-298 including an optical counterpart
  25. MAXI GRB210501.83: Global MASTER-Net observations report
  26. MAXI GRB210320.89: Global MASTER-Net observations report
  27. GRB 210320A: MAXI/GSC detection
  28. Konus-Wind detection of GRB 210222A
  29. GRB 210222A: CALET Gamma-Ray Burst Monitor detection
  30. GRB 210222A: MAXI/GSC detection
  31. SGR 1935+2154: MAXI/GSC detection
  32. NuEm-210111A: MAXI/GSC upper limit
  33. MAXI GRB210110.64: Global MASTER-Net observations report
  34. GRB 210110A: MAXI/GSC detection
  35. GRB 210109A: MAXI/GSC detection
  36. GRB 210102B: further Swift-XRT observations
  37. GRB 210102B: Assy optical afterglow identification
  38. GRB 210104A: Swift/UVOT Detection
  39. GRB 210102B: Tiled Swift observations
  40. GRB 210102B: Assy optical observations
  41. GRB 210102B: Swift-XRT observations
  42. MAXI GRB210102.38: Global MASTER-Net observations report
  43. GRB 210102B: Tiled Swift observations
  44. GRB 210102B: MAXI/GSC detection
  45. IceCube-201209A : MAXI/GSC upper limit
  46. MAXI GRB201021.68: Global MASTER-Net observations report
  47. GRB 201021B MAXI/GSC detection
  48. GRB 200903D: MAXI/GSC detection
  49. GRB 200809B: Fermi GBM detection
  50. GRB 200809B: Swift-XRT afterglow detection
  51. GRB 200809B: MAXI/GSC detection
  52. GRB 200615B: CALET Gamma-Ray Burst Monitor detection
  53. GRB 200615B: MAXI/GSC detection
  54. GRB 200517A: Swift-XRT Confirmation of afterglow
  55. Fermi GBM Sub-Threshold Detection of GRB 200517A
  56. GRB 200517A: Swift-XRT afterglow detection
  57. GRB 200514A: AstroSat CZTI detection
  58. GRB 200517A: Tiled Swift observations
  59. GRB 200517A: MAXI/GSC detection
  60. GRB 200514A: MITSuME Akeno optical upper limits
  61. GRB 200514A: CALET Gamma-Ray Burst Monitor detection
  62. GRB 200514A: MAXI/GSC detection
  63. Konus-Wind observation of a very intense bursting activity of SGR 1935+2154
  64. SGR 1935+2154: MAXI/GSC detection
  65. GRB 200320B: MAXI/GSC detection
  66. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  67. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  68. GRB 200310A: MAXI/GSC detection
  69. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  70. LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
  71. LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
  72. LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
  73. LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
  74. LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
  75. GRB 200205A = Swift J0840.7-3516, A newly discovered transient X-ray Pulsar
  76. GRB 200205A / Swift trigger 954304: VLT optical observations
  77. GRB 200205A: MAXI/GSC detection
  78. MAXI GRB200205.29: Global MASTER-Net observations report
  79. LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations
  81. IceCube-200117A: No Neutrino Counterpart in ANTARES data
  82. LIGO/Virgo S200115j: Coverage and upper limits from MAXI/GSC observations
  83. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  84. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  85. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  86. GRB 200105A: MAXI/GSC detection
  87. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  88. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  89. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  90. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  91. LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
  92. LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
  93. LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
  94. LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
  95. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  96. LIGO/Virgo S191105e: Coverage and upper limits from MAXI/GSC observations
  97. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  98. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  99. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  100. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations

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