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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"

2858 results found.

  1. IceCube-221223A: JCMT/SCUBA2 observations
  2. GRB 230101A: AstroSat CZTI detection
  3. GRB 221226B: Swift detection of a burst
  4. Swift GRB221226.95: Global MASTER-Net observations report
  5. IceCube Alert 221224.04: Global MASTER-Net observations report
  6. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  7. Swift GRB221215.15: Global MASTER-Net observations report
  8. Fermi trigger No 692713692: Global MASTER-Net observations report
  9. Fermi GRB 221211A: Global MASTER-Net observations report
  10. GRB 221208A: AstroSat CZTI detection
  11. GRB 221209A: AstroSat CZTI detection
  12. GRB 221203C: AstroSat CZTI detection
  13. GRB 221206A: Fermi GBM Final Real-time Localization
  14. GRB 221202B: Detection by VZLUSAT-2
  15. GRB 221126A: AstroSat CZTI detection
  16. GRB221121A: AstroSat CZTI detection
  17. LAT GRB221119.63: Global MASTER-Net observations report
  18. GRB 221115B: Swift/BAT-GUANO arcminute localization
  19. GRB 221104A: Fermi GBM Final Localization
  20. GRB 221108A: Fermi GBM Final Localization
  21. Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)
  22. GRB 221027C: AstroSat CZTI detection
  23. SGR 1935+2154: AstroSat CZTI Detections
  24. GRB 221025A: AstroSat CZTI detection
  25. LAT GRB221025.04: Global MASTER-Net observations report
  26. GRB 221022B: AstroSat CZTI detection
  27. GRB 221009A: Determination of the black holes mass and spin
  28. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  29. GRB 221009A: A type I BdHN of exceptional energetics
  30. GRB 221016A: Swift detection of a burst
  31. Konus-Wind observation of the recent SGR 1935+2154 activity
  32. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  33. GRB 221009A: Gemini-South Infrared Afterglow Detection
  34. MAXI GRB 221006A: Redshifts of the possible host galaxies
  35. GRB 221006A: Swift-XRT afterglow detection
  36. GRB 221013A: Fermi GBM Final Real-time Localization
  37. Afterglow limits of GRB 221006A from OHP
  38. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  39. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  40. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  41. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  42. GRB 221006A: Swift-XRT observations
  43. GRB 221006A: MAXI/GSC detection
  44. Fermi trigger No 686403226: Global MASTER-Net observations report
  45. Fermi trigger No 686350260: Global MASTER-Net observations report
  46. GRB 220930A: AstroSat CZTI detection
  47. GRB 220930A: LCOGT Optical Upper Limits
  48. Fermi GRB 220925A: Global MASTER-Net observations report
  49. Fermi trigger No 685748699: Global MASTER-Net observations report
  50. LAT GRB220921.46: Global MASTER-Net observations report
  51. Fermi trigger No 684716840: Global MASTER-Net observations report
  52. Fermi GRB 220912A: Global MASTER-Net observations report
  53. GRB 220912A: AstroSat CZTI detection
  54. IPN triangulation of GRB 220905A
  55. GRB 220910A: AstroSat CZTI detection
  56. IPN triangulation of GRB 220903A (long)
  57. Fermi GRB 220902A: Global MASTER-Net observations report
  58. Fermi trigger No 683646997: Global MASTER-Net observations report
  59. IceCube-220822A: No significant detection in HAWC
  60. Fermi trigger No 683202084: Global MASTER-Net observations report
  61. Fermi trigger No 683183601: Global MASTER-Net observations report
  62. Fermi trigger No 682918137: Global MASTER-Net observations report
  63. Fermi trigger No 681998863: Global MASTER-Net observations report
  64. GRB 220810A: MeerLICHT detection of two afterglow candidates
  65. GRB 220810A: Fermi GBM Final Real-time Localization
  66. IceCube Alert 220808.33: Global MASTER-Net observations report
  67. GRB 220803A: AstroSat CZTI detection
  68. GRB 220729A: AstroSat CZTI detection
  69. Fermi trigger No 680782656: Global MASTER-Net observations report
  70. Fermi GRB 220728A: Global MASTER-Net observations report
  71. GRB 220726A: Fermi GBM Final Real-time Localization
  72. Fermi GRB 220724A: Global MASTER-Net observations report
  73. Fermi GRB 220721A: Global MASTER-Net observations report
  74. GRB 220715B: Swift detection of a burst
  75. GRB 220715B: Fermi GBM Final Real-time Localization
  76. Fermi GRB 220711B: Global MASTER-Net observations report
  77. GRB 220707A: AstroSat CZTI detection
  78. GRB 220702B: AstroSat CZTI detection
  79. MAXI GRB220706.73: Global MASTER-Net observations report
  80. GRB 220627A: AstroSat CZTI detection
  81. Fermi trigger No 678058621: Global MASTER-Net observations report
  82. Fermi GRB 220624A: Global MASTER-Net observations report
  83. IceCube Alert 220624.68: Global MASTER-Net observations report
  84. GRB 220623A: AstroSat CZTI detection
  85. GRB 220623A: iTelescope optical upper limit
  86. GRB 220623A: Swift detection of a burst
  87. Fermi trigger No 677377371: Global MASTER-Net observations report
  88. GRB 220619A: AstroSat CZTI detection
  89. GRB 220610B: AstroSat CZTI detection
  90. Fermi GRB 220610A: Global MASTER-Net observations report
  91. Fermi trigger No 676537486: Global MASTER-Net observations report
  92. GRB 220609B: AstroSat CZTI detection
  93. GRB 220608A: AstroSat CZTI detection
  94. MAXI GRB220607.31: Global MASTER-Net observations report
  95. MAXI GRB220607.41: Global MASTER-Net observations report
  96. GRB 220527A: A BdHN I with a clear UPE phase
  97. GRB 220527A: AstroSat CZTI detection
  98. IPN triangulation of GRB 220525A
  99. GRB 220514A: AstroSat CZTI detection
  100. Fermi GRB 220513A: Global MASTER-Net observations report

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