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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

27967 results found.

  1. GRB 210528A: AstroSat CZTI detection
  2. GRB 210528B: MAXI/GSC detection
  3. GRB 210527A: Swift-BAT refined analysis
  4. GRB 210528A: Fermi GBM Final Real-time Localization
  5. GRB 210527A: Swift/UVOT Observations
  6. GRB 210527A: GIT optical upper limit
  7. Swift GRB 210527A: Global MASTER-Net observations report
  8. GRB 210527A: Swift-XRT refined Analysis
  9. GRB 210527A: Enhanced Swift-XRT position
  10. GRB 210527A: Swift-XRT observations
  11. GRB 210527A: Swift detection of a burst
  12. Konus-Wind detection of GRB 210524A
  13. IPN triangulation of GRB 210524A
  14. GRB 210524B: Fermi GBM Final Real-time Localization
  15. GRB 210524A: Fermi GBM Final Real-time Localization
  16. GRB 210522A: GECAM detection
  17. GRB 210520A: Swift-XRT observations
  18. GRB 210521A: MAXI/GSC detection
  19. GRB210413B: further Swift-XRT observations
  20. GRB 210520A: Fermi GBM detection
  21. GRB 210520A: Tiled Swift observations
  22. GRB 210520A: Fermi-LAT detection
  23. GRB 210520A: GECAM detection
  24. GRB 210520A: Fermi GBM Final Real-time Localization
  25. GRB 210517A: KCT optical upper limit
  26. IceCube GCN alert 135302_36915486.amon retraction
  27. IPN triangulation of GRB 210518A
  28. GRB 210519A: Fermi GBM Final Localization
  29. Konus-Wind detection of GRB 210514A
  30. GRB 210518A: Fermi GBM Final Real-time Localization
  31. GRB 210517A: Swift-BAT refined analysis
  32. GRB 210517A: Swift-XRT refined Analysis
  33. IceCube-210516A: No significant detection in HAWC
  34. GRB 210517A: Swift/UVOT Upper Limits
  35. GRB 210515C: Swift/UVOT Upper Limits
  36. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  37. GRB 210517A: AGILE detection
  38. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  39. GRB 210517A: Enhanced Swift-XRT position
  40. Swift GRB 210517A: Global MASTER-Net observations report
  41. GRB 210517A: Swift detection of a burst
  42. GRB 210516A: Fermi GBM Final Real-time Localization
  43. GRB 210515C: LCO Optical Upper Limit
  44. GRB 210504A: LCO Optical Afterglow Detection
  45. IceCube-210516A - IceCube observation of a high-energy neutrino candidate track-like event
  46. GRB 210514A: Swift/UVOT Upper Limits
  47. AMON IC_HAWC NuEm-210515A / NuEm-210515B : No neutrino counterpart detected with ANTARES
  48. GRB 210515C: Swift-XRT refined Analysis
  49. Swift GRB210515.83: Global MASTER-Net observations report
  50. GRB 210515C: Swift-BAT refined analysis
  51. GRB 210515C: Swift detection of a burst
  52. GRB 210514A: Swift-BAT refined analysis
  53. GRB 210515B: Fermi GBM Final Real-time Localization
  54. GRB 210515A: Fermi GBM Final Real-time Localization
  55. Swift GRB210514.71: Global MASTER-Net observations report
  56. GRB 210514A: Swift XRT light curve is fading
  57. GRB 210514A: Swift-XRT refined Analysis
  58. GRB 210514A: Enhanced Swift-XRT position
  59. GRB 210514A: update on the BAT trigger time and burst duration
  60. GRB 210514A: Swift detection of a burst
  61. Konus-Wind detection of GRB 210511B
  62. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  63. IPN triangulation of GRB 210511B
  64. Short GRB 210323A: likely host galaxy detection
  65. IPN triangulation of GRB 210427A
  66. GRB 210511B: AGILE detection
  67. GRB 210511B: GECAM detection
  68. GRB 210511B: Fermi GBM Final Real-time Localization
  69. GRB 210511A: Fermi GBM Final Real-time Localization
  70. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  71. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  72. Swift trigger 1047857 is 4U 1700-377
  73. GRB 210510A: Fermi GBM Final Real-time Localization
  74. GRB 210509A: RATIR Optical and NIR Upper Limits
  75. GRB 210509A: Swift/UVOT Upper Limits
  76. GRB 210509A: Swift-XRT refined Analysis
  77. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  78. GRB 210509A: Swift-BAT refined analysis
  79. Swift GRB 210509A: Global MASTER-Net observations report
  80. GRB 210509A: Enhanced Swift-XRT position
  81. GRB 210509A: BOOTES-4/MET optical upper limit
  82. GRB 210509A: Swift-XRT observations
  83. GRB 210509A: Swift detection of a burst
  84. GRB 210506A: Swift/BAT-GUANO position retraction
  85. IPN triangulation of GRB 210506A
  86. HAWC-210507A: No neutrino counterpart candidates in ANTARES search
  87. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  88. GRB 210507A: Fermi GBM Final Real-time Localization
  89. GRB 210506A: Swift-XRT observations
  90. ZTF21aayokph (AT2021lfa): MASTER OT detection 3h befor ZTF
  91. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  92. Lowell Discovery Telescope Observations of ZTF21aayokph (AT2021lfa)
  93. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  94. GRB 210506A: Swift ToO observations
  95. ZTF21aayokph (AT2021lfa): Nanshan/NEXT optical upper limit
  96. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  97. GRB 210504A: Lowell Discovery Telescope optical observations
  98. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  99. GRB 210504A: VLT X-shooter redshift
  100. GRB 210424B: AstroSat CZTI detection

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