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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"

3039 results found.

  1. Fermi trigger No 658971499: Global MASTER-Net observations report
  2. Fermi trigger No 658755664: Global MASTER-Net observations report
  3. Fermi GRB 211112A: Global MASTER-Net observations report
  4. IPN triangulation of GRB 211106A (short)
  5. Fermi trigger No 658214822: Global MASTER-Net observations report
  6. Fermi GRB 211109B: Global MASTER-Net observations report
  7. GRB 211023B: MITSuME Akeno optical upper limits
  8. Fermi GRB 211031A: Global MASTER-Net observations report
  9. GRB 211023A: continued Mondy optical observations
  10. Fermi GRB 211027A: Global MASTER-Net observations report
  11. GRB 211024A: Swift-XRT observations
  12. Swift GRB 211025A: Global MASTER-Net observations report
  13. GRB 211023A: 1.5m OSN optical observation
  14. Fermi GRB 211024A: Global MASTER-Net observations report
  15. Fermi trigger No 656288898: Global MASTER-Net observations report
  16. Fermi trigger No 655673024: Global MASTER-Net observations report
  17. Fermi trigger No 655646385: Global MASTER-Net observations report
  18. Swift GRB211010.45: Global MASTER-Net observations report
  19. Fermi Gamma-ray Burst Monitor trigger 211008665/655401471 is not a GRB
  20. GRB 211008A: BALROG localization (Fermi Trigger 655401471 / GRB 211008665)
  21. Fermi trigger No 655401471: Global MASTER-Net observations report
  22. Fermi GRB 210929B: Global MASTER-Net observations report
  23. GRB 210927A: Fermi GBM Final Real-time Localization
  24. Fermi trigger No 653151835: Global MASTER-Net observations report
  25. GRB 210912A: Mondy optical afterglow confirmation
  26. Swift GRB 210912A: Global MASTER-Net observations report
  27. Fermi trigger No 653093506: Global MASTER-Net observations report
  28. Fermi trigger No 653083551: Global MASTER-Net observations report
  29. Fermi trigger No 653079281: Global MASTER-Net observations report
  30. Fermi trigger No 653022153: Global MASTER-Net observations report
  31. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  32. Fermi trigger No 652927551: Global MASTER-Net observations report
  33. Fermi trigger No 652911693: Global MASTER-Net observations report
  34. Fermi trigger No 652906639: Global MASTER-Net observations report
  35. Fermi GRB 210909A: Global MASTER-Net observations report
  36. Fermi trigger No 652585475: Global MASTER-Net observations report
  37. GRB 210610A: Maidanak and AbAO optical observations
  38. Fermi GRB 210904A: Global MASTER-Net observations report
  39. Fermi GRB 210827A: Global MASTER-Net observations report
  40. Fermi GRB 210827B: Global MASTER-Net observations report
  41. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  42. Swift GRB 210820A: Global MASTER-Net observations report
  43. Swift GRB210818.68: Global MASTER-Net observations report
  44. Konus-Wind detection of GRB 210818A
  45. Fermi GRB 210812A: Global MASTER-Net observations report
  46. IceCube Alert 210811.09: Global MASTER-Net observations report
  47. Fermi GRB 210807C: Global MASTER-Net observations report
  48. GRB 210807C: Swift detection of a burst
  49. Fermi trigger No 649814537: Global MASTER-Net observations report
  50. Fermi trigger No 649627691: Global MASTER-Net observations report
  51. GRB 210801A: Fermi GBM detection
  52. GRB 210731A: Swift-BAT refined analysis
  53. GRB 210801A: BALROG localization (Fermi Trigger 649519043 / GRB 210801581)
  54. Swift GRB210731.93: Global MASTER-Net observations report
  55. GRB 210730A: TNG optical observations
  56. GRB 210730A: Fermi GBM observation
  57. GRB 210730A: AstroSat CZTI detection
  58. GRB 210730A: Swift detection of a burst near M82
  59. Fermi trigger No 649072251: Global MASTER-Net observations report
  60. Fermi trigger No 648959581: Global MASTER-Net observations report
  61. Fermi trigger No 648278666: Global MASTER-Net observations report
  62. GRB 210712A: Swift-BAT refined analysis
  63. Fermi trigger No 647805873: Global MASTER-Net observations report
  64. GRB 210704A: Lowell Discovery Telescope Optical Observations
  65. Fermi trigger No 647624281: Global MASTER-Net observations report
  66. MAXI GRB210709.93: Global MASTER-Net observations report
  67. Fermi trigger No 647365516: Global MASTER-Net observations report
  68. Integral GRB210707.02: Global MASTER-Net observations report
  69. GRB 210704A: OSIRIS/GTC spectroscopy
  70. Konus-Wind detection of GRB 210704A
  71. GRB 210704A: TNG detection of the optical afterglow candidate
  72. GRB 210704A: Assy optical afterglow candidate
  73. GRB 210702A: iTelescope optical afterglow observations
  74. GRB 210627B: GECAM detection
  75. Fermi GRB 210627B: Global MASTER-Net observations report
  76. GRB 210627B: BALROG localization (Fermi Trigger 646509445/ GRB 210627748)
  77. GRB 210627B: Fermi GBM Final Real-time Localization
  78. Fermi GRB 210627A: Global MASTER-Net observations report
  79. Fermi GRB 210626A: Global MASTER-Net observations report
  80. GRB 150428A: late-time radio observations
  81. Fermi trigger No 646189108: Global MASTER-Net observations report
  82. Fermi trigger No 646194855: Global MASTER-Net observations report
  83. Fermi GRB 210622B: Global MASTER-Net observations report
  84. GRB 210619B: Liverpool Telescope r'-band observations
  85. Fermi trigger No 645857659: Global MASTER-Net observations report
  86. Swift GRB210619.99: Global MASTER-Net observations report
  87. Fermi GRB 210615A: Global MASTER-Net observations report
  88. GRB 210610B: Swift-BAT refined analysis
  89. Fermi trigger No 645047470: Global MASTER-Net observations report
  90. GRB 210610A: MITSuME Ishigaki optical observation
  91. Fermi GRB 210606A: Global MASTER-Net observations report
  92. SGR J1555.2-5402: Swift-BAT refined analysis
  93. Fermi trigger No 644359567: Global MASTER-Net observations report
  94. Fermi GRB 210601A: Global MASTER-Net observations report
  95. Fermi GRB 210529B: Global MASTER-Net observations report
  96. GRB 210528B: MITSuME Akeno optical upper limits
  97. Fermi GRB 210528A: Global MASTER-Net observations report
  98. Fermi trigger No 643065622: Global MASTER-Net observations report
  99. Fermi GRB 210518A: Global MASTER-Net observations report
  100. Konus-Wind detection of GRB 210514A

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