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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"

3724 results found.

  1. GRB 221028A: CrAO/ZTSh optical upper limit
  2. GRB 221028B: MAXI/GSC detection
  3. Konus-Wind detection of GRB 221017A
  4. Swift GRB 221027B: Global MASTER-Net observations report
  5. GRB 221022B: Detection by GRBAlpha
  6. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  7. GRB 221017A: Swift-XRT observations
  8. GRB 221017A: Swift ToO observations
  9. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  10. IPN triangulation of GRB 221017A (long)
  11. MAXI GRB221017.24: Global MASTER-Net observations report
  12. GRB 221017A: MAXI/GSC detection
  13. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  14. MAXI GRB 221006A: Redshifts of the possible host galaxies
  15. Fermi trigger No 687340841: Global MASTER-Net observations report
  16. GRB 221006A: Swift-XRT afterglow detection
  17. Fermi trigger No 687281393: Global MASTER-Net observations report
  18. Afterglow limits of GRB 221006A from OHP
  19. GRB 221009A: NICER follow-up observations
  20. Fermi trigger No 687190301: Global MASTER-Net observations report
  21. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  22. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  23. GRB 221006A: Swift ToO observations
  24. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  25. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  26. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  27. GRB 221008A: Swift-XRT observations
  28. GRB 221008A: Tiled Swift observations
  29. GRB 221008A: MAXI/GSC detection
  30. GRB 221006A: Swift-XRT observations
  31. GRB 221006A: Tiled Swift observations
  32. GRB 221006A: MAXI/GSC detection
  33. Fermi trigger No 686588176: Global MASTER-Net observations report
  34. GRB 220927A: Fermi GBM Final Localization
  35. Fermi GRB 220925A: Global MASTER-Net observations report
  36. Fermi trigger No 685748699: Global MASTER-Net observations report
  37. Fermi trigger No 685452089: Global MASTER-Net observations report
  38. IceCube-220907A: No significant detection in HAWC
  39. Fermi trigger No 684716840: Global MASTER-Net observations report
  40. Fermi GRB 220912A: Global MASTER-Net observations report
  41. IceCube Alert 220907.28: Global MASTER-Net observations report
  42. Fermi GRB 220905A: Global MASTER-Net observations report
  43. Fermi GRB 220902A: Global MASTER-Net observations report
  44. Fermi trigger No 683537972: Global MASTER-Net observations report
  45. Fermi trigger No 683202084: Global MASTER-Net observations report
  46. Fermi trigger No 683183601: Global MASTER-Net observations report
  47. GRB 220825A: Fermi GBM observation
  48. GRB 220825A: Swift/BAT-GUANO detection
  49. GRB 220825A: Fermi GBM Final Localization
  50. Fermi trigger No 682918137: Global MASTER-Net observations report
  51. Fermi trigger No 681719116: Global MASTER-Net observations report
  52. Fermi trigger No 681271717: Global MASTER-Net observations report
  53. Fermi trigger No 680782656: Global MASTER-Net observations report
  54. Fermi GRB 220728A: Global MASTER-Net observations report
  55. GRB 220715B: BOOTES-network optical upper limits
  56. Fermi trigger No 679248723: Global MASTER-Net observations report
  57. Fermi GRB 220711B: Global MASTER-Net observations report
  58. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  59. MAXI GRB220706.73: Global MASTER-Net observations report
  60. GRB 200701A: KAIT Optical Upper Limit
  61. Trigger 1113743: Swift detection of MAXI J0655-013
  62. Fermi trigger No 678058621: Global MASTER-Net observations report
  63. IceCube Alert 220627.74: Global MASTER-Net observations report
  64. Fermi GRB 220623B: Global MASTER-Net observations report
  65. GRB 220624A: AGILE detection
  66. Swift Detection of MAXI J0655-013
  67. GRB 220618A: Swift-BAT refined analysis
  68. Fermi trigger No 677377371: Global MASTER-Net observations report
  69. Fermi trigger No 677307509: Global MASTER-Net observations report
  70. Fermi trigger No 677174940: Global MASTER-Net observations report
  71. IPN triangulation of GRB 220613A
  72. Fermi trigger No 676909037: Global MASTER-Net observations report
  73. Fermi GRB 220610A: Global MASTER-Net observations report
  74. MAXI GRB220607.31: Global MASTER-Net observations report
  75. MAXI GRB220607.41: Global MASTER-Net observations report
  76. Konus-Wind detection of GRB 220601A
  77. Fermi trigger No 675992935: Global MASTER-Net observations report
  78. Fermi trigger No 675411172: Global MASTER-Net observations report
  79. GRB 220521A: ISON-Castelgrande observatory optical observations
  80. Swift GRB220521.97: Global MASTER-Net observations report
  81. Konus-Wind detection of GRB 220506A
  82. Konus-Wind detection of GRB 220514B
  83. GRB 220514B: Swift-XRT observations
  84. GRB 220514B: Tiled Swift observations
  85. IceCube-220513A: No significant detection in HAWC
  86. GRB 220514B: MAXI/GSC detection
  87. MAXI GRB220514.98: Global MASTER-Net observations report
  88. Integral GRB220514.52: Global MASTER-Net observations report
  89. Fermi GRB 220514A: Global MASTER-Net observations report
  90. Fermi GRB 220513A: Global MASTER-Net observations report
  91. Konus-Wind detection of GRB 220511A
  92. GRB 220511A: Swift/BAT-GUANO arcminute localization
  93. GRB 220511A: AGILE detection
  94. Fermi trigger No 673846271: Global MASTER-Net observations report
  95. GRB 220506A: MITSuME Akeno optical upper limits
  96. GRB 220506A: GIT optical upper limit.
  97. GRB 220506A: BOOTES-5/JGT optical upper limit
  98. GRB 220506A: Swift-XRT afterglow detection
  99. GRB 220506A: Tiled Swift observations
  100. Swift GRB220506.51: Global MASTER-Net observations report

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