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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"

647 results found.

  1. GRB 240109A: Swift-BAT refined analysis
  2. GRB 231215A: radio detection with the VLA
  3. GRB 231129A: Swift-BAT refined analysis
  4. GRB 231129A: BOOTES-5/JGT optical upper limit
  5. GRB 231118A: Swift-BAT refined analysis
  6. GRB 231111A: Swift-BAT refined analysis
  7. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  8. IceCube Alert 231027.18: Global MASTER-Net observations report
  9. GRB 230919A: AstroSat CZTI detection
  10. GRB 230911C: Swift-BAT refined analysis
  11. GRB 230826A: Swift-BAT refined analysis
  12. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  13. Fermi GRB 230827A: Global MASTER-Net observations report
  14. Swift GRB230825.75: Global MASTER-Net observations report
  15. Fermi GRB 230814A: Global MASTER-Net observations report
  16. Swift GRB230728.12: Global MASTER-Net observations report
  17. Fermi-LAT gamma-ray observations of IceCube-230725A
  18. IceCube-230725A - IceCube observation of a high-energy neutrino candidate track-like event
  19. LIGO/Virgo S230622e: Global MASTER-Net observations report
  20. LIGO/Virgo S230615be: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  22. GRB 230430A: AstroSat CZTI detection
  23. IPN triangulation of GRB 230418A (short)
  24. Fermi GRB 230402A: Global MASTER-Net observations report
  25. Fermi GRB 230227A: Global MASTER-Net observations report
  26. Fermi GRB 230215A: Global MASTER-Net observations report
  27. GRB 221231A: Fermi GBM Observation
  28. GRB 230101A: AstroSat CZTI detection
  29. Fermi GRB 221223A: Global MASTER-Net observations report
  30. GRB 221216A: Swift-XRT refined Analysis
  31. Fermi trigger No 687190301: Global MASTER-Net observations report
  32. GRB 220831A: ATCA 5/9 GHz radio observations
  33. GRB 220711B: Fermi GBM Detection
  34. GRB 220624A: Fermi GBM Detection
  35. Fermi GRB 220623B: Global MASTER-Net observations report
  36. GRB 220623A: Swift-XRT observations
  37. Konus-Wind detection of an intermediate flare from SGR 1935+2154 on June 16
  38. Swift GRB220521.97: Global MASTER-Net observations report
  39. GRB 220514B: MAXI/GSC detection
  40. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  41. MAXI GRB220506.27: Global MASTER-Net observations report
  42. IceCube Alert 220501.95: Global MASTER-Net observations report
  43. GRB 220319A: Mondy optical uper limit
  44. GRB 220315A: MASTER Global Robotic Net optical observations
  45. Konus-Wind detection of GRB 220310A
  46. Fermi trigger No 668410535: Global MASTER-Net observations report
  47. Swift GRB 220306B: Global MASTER-Net observations report
  48. Konus-Wind observation of GRB 220219B
  49. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  50. GRB 220130A: Fermi GBM Observation
  51. Konus-Wind detection of GRB 220107A
  52. Konus-Wind detection of GRB 210928A
  53. Swift GRB 210919A: Global MASTER-Net observations report
  54. Konus-Wind detection of GRB 210905A
  55. Integral GRB210829.17: Global MASTER-Net observations report
  56. Integral GRB210829.14: Global MASTER-Net observations report
  57. GRB 210807C: Fermi GBM detection
  58. Konus-Wind detection of GRB 210702A
  59. Fermi trigger No 646194855: Global MASTER-Net observations report
  60. Swift GRB210618.07: Global MASTER-Net observations report
  61. Swift Detection of probable new Swift SGR J1555.2-5402
  62. Fermi GRB 210528A: Global MASTER-Net observations report
  63. GRB 210521A: MAXI/GSC detection
  64. GRB 210514A: update on the BAT trigger time and burst duration
  65. Swift Trigger 1045571 is not a GRB
  66. GRB 210419A: Swift-BAT refined analysis
  67. GRB 210410A: Swift-XRT refined Analysis
  68. Fermi trigger No 639199407: Global MASTER-Net observations report
  69. GRB 210403A: Swift-BAT refined analysis
  70. GRB 210318B: Swift-BAT refined analysis
  71. GRB 210204A: AstroSat CZTI Detection
  72. Fermi GRB 210120A: Global MASTER-Net observations report
  73. Fermi trigger No 631602681: Global MASTER-Net observations report
  74. GRB 210104A: GWAC-F60A optical afterglow observations
  75. GRB 201223A: Swift/UVOT Detection
  76. Konus-Wind detection of GRB 201216C
  77. Trigger 1007266: Swift detection of 1A 0535+262
  78. Swift Trigger 1006917 is Be/X-ray binary pulsar 1A 0535+262
  79. IceCube Alert 201014.09: Global MASTER-Net observations report
  80. GRB 201004A: Fermi GBM Final Localization
  81. Fermi trigger No 622618714: Global MASTER-Net observations report
  82. IPN triangulation of GRB 200916B (short)
  83. GRB 200903A: Fermi GBM detection
  84. Swift Trigger 992444 is due to detector noise
  85. Swift Trigger 990358 is due to detector noise
  86. Swift Trigger 989458 is due to detector noise
  87. Fermi GRB 200723A: Global MASTER-Net observations report
  88. GRB 200630A: Swift-BAT refined analysis
  89. GRB 200529A: Swift-BAT refined analysis
  90. GRB 200528A: Swift-BAT refined analysis
  91. Konus-Wind detection of short/hard GRB 200521A
  92. GRB 200519A: Swift-BAT refined analysis
  93. SGR 1935+2154: AstroSat CZTI detection
  94. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  95. GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations
  96. GRB 200416A: Swift-BAT refined analysis
  97. Fermi trigger No 607537834: Global MASTER-Net observations report
  98. Fermi trigger No 606799116: Global MASTER-Net observations report
  99. Konus-Wind observation of GRB 200313A
  100. SGR Swift J1818.0-1607: Swift-BAT refined analysis

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