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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"

3735 results found.

  1. Fermi GRB 221226A: Global MASTER-Net observations report
  2. Fermi GRB 221221A: Global MASTER-Net observations report
  3. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  4. Integral GRB221218.34: Global MASTER-Net observations report
  5. Fermi trigger No 692713692: Global MASTER-Net observations report
  6. Swift Trigger 1144538 is not a GRB
  7. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
  8. Fermi GRB 221211A: Global MASTER-Net observations report
  9. IceCube Alert 221210.36: Global MASTER-Net observations report
  10. IceCube Alert 221124.66: Global MASTER-Net observations report
  11. LAT GRB221119.63: Global MASTER-Net observations report
  12. GRB 221028A: CrAO/ZTSh optical upper limit
  13. GRB 221028B: MAXI/GSC detection
  14. Konus-Wind detection of GRB 221017A
  15. Swift GRB 221027B: Global MASTER-Net observations report
  16. GRB 221022B: Detection by GRBAlpha
  17. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  18. GRB 221017A: Swift-XRT observations
  19. GRB 221017A: Swift ToO observations
  20. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  21. IPN triangulation of GRB 221017A (long)
  22. MAXI GRB221017.24: Global MASTER-Net observations report
  23. GRB 221017A: MAXI/GSC detection
  24. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  25. MAXI GRB 221006A: Redshifts of the possible host galaxies
  26. Fermi trigger No 687340841: Global MASTER-Net observations report
  27. GRB 221006A: Swift-XRT afterglow detection
  28. Fermi trigger No 687281393: Global MASTER-Net observations report
  29. Afterglow limits of GRB 221006A from OHP
  30. GRB 221009A: NICER follow-up observations
  31. Fermi trigger No 687190301: Global MASTER-Net observations report
  32. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  33. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  34. GRB 221006A: Swift ToO observations
  35. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  36. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  37. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  38. GRB 221008A: Swift-XRT observations
  39. GRB 221008A: Tiled Swift observations
  40. GRB 221008A: MAXI/GSC detection
  41. GRB 221006A: Swift-XRT observations
  42. GRB 221006A: Tiled Swift observations
  43. GRB 221006A: MAXI/GSC detection
  44. Fermi trigger No 686588176: Global MASTER-Net observations report
  45. GRB 220927A: Fermi GBM Final Localization
  46. Fermi GRB 220925A: Global MASTER-Net observations report
  47. Fermi trigger No 685748699: Global MASTER-Net observations report
  48. Fermi trigger No 685452089: Global MASTER-Net observations report
  49. IceCube-220907A: No significant detection in HAWC
  50. Fermi trigger No 684716840: Global MASTER-Net observations report
  51. Fermi GRB 220912A: Global MASTER-Net observations report
  52. IceCube Alert 220907.28: Global MASTER-Net observations report
  53. Fermi GRB 220905A: Global MASTER-Net observations report
  54. Fermi GRB 220902A: Global MASTER-Net observations report
  55. Fermi trigger No 683537972: Global MASTER-Net observations report
  56. Fermi trigger No 683202084: Global MASTER-Net observations report
  57. Fermi trigger No 683183601: Global MASTER-Net observations report
  58. GRB 220825A: Fermi GBM observation
  59. GRB 220825A: Swift/BAT-GUANO detection
  60. GRB 220825A: Fermi GBM Final Localization
  61. Fermi trigger No 682918137: Global MASTER-Net observations report
  62. Fermi trigger No 681719116: Global MASTER-Net observations report
  63. Fermi trigger No 681271717: Global MASTER-Net observations report
  64. Fermi trigger No 680782656: Global MASTER-Net observations report
  65. Fermi GRB 220728A: Global MASTER-Net observations report
  66. GRB 220715B: BOOTES-network optical upper limits
  67. Fermi trigger No 679248723: Global MASTER-Net observations report
  68. Fermi GRB 220711B: Global MASTER-Net observations report
  69. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  70. MAXI GRB220706.73: Global MASTER-Net observations report
  71. GRB 200701A: KAIT Optical Upper Limit
  72. Trigger 1113743: Swift detection of MAXI J0655-013
  73. Fermi trigger No 678058621: Global MASTER-Net observations report
  74. IceCube Alert 220627.74: Global MASTER-Net observations report
  75. Fermi GRB 220623B: Global MASTER-Net observations report
  76. GRB 220624A: AGILE detection
  77. Swift Detection of MAXI J0655-013
  78. GRB 220618A: Swift-BAT refined analysis
  79. Fermi trigger No 677377371: Global MASTER-Net observations report
  80. Fermi trigger No 677307509: Global MASTER-Net observations report
  81. Fermi trigger No 677174940: Global MASTER-Net observations report
  82. IPN triangulation of GRB 220613A
  83. Fermi trigger No 676909037: Global MASTER-Net observations report
  84. Fermi GRB 220610A: Global MASTER-Net observations report
  85. MAXI GRB220607.31: Global MASTER-Net observations report
  86. MAXI GRB220607.41: Global MASTER-Net observations report
  87. Konus-Wind detection of GRB 220601A
  88. Fermi trigger No 675992935: Global MASTER-Net observations report
  89. Fermi trigger No 675411172: Global MASTER-Net observations report
  90. GRB 220521A: ISON-Castelgrande observatory optical observations
  91. Swift GRB220521.97: Global MASTER-Net observations report
  92. Konus-Wind detection of GRB 220506A
  93. Konus-Wind detection of GRB 220514B
  94. GRB 220514B: Swift-XRT observations
  95. GRB 220514B: Tiled Swift observations
  96. IceCube-220513A: No significant detection in HAWC
  97. GRB 220514B: MAXI/GSC detection
  98. MAXI GRB220514.98: Global MASTER-Net observations report
  99. Integral GRB220514.52: Global MASTER-Net observations report
  100. Fermi GRB 220514A: Global MASTER-Net observations report

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